MPPEB Group 2 Subgroup 4 Labour Inspector Official Paper(Held On: 12th Jan 2017 Shift 2) (Previous Year Paper)

The correct answer is Rough stone.

Concept:

Friction force:

• Friction is the force that resists motion when the surface of one object comes into contact with the surface of another.
• It is a force that opposes the relative motion of two bodies in contact.
• The frictional force acts in a direction opposite to the direction of motion of the bodies in contact.
• Frictional force prevents objects from gliding and ensures contact.
• Friction forces also provide a significant amount of resistance to motion.

Explanation:

• To sharpen the blade of a knife on high-frictional surfaces is preferable.
• The friction between the surface and the blade is greater on harder surfaces.
• A stone will be more suitable to sharpen the blade of a knife by rubbing it against a surface.
• It will provide a greater reaction and thus a higher friction force, making it easier to sharpen the blade of a knife by rubbing.

Thus, to sharpen the blade of a knife by rubbing it against a surface,  Rough stone will be most suitable.

Additional InformationWooden blocks: 

• Wooden blocks may be considered hard in comparison to plastic wood, but in general, or in comparison to stone wood is not a very hard material.

Plastic blocks: 

• Plastic blocks are easily deformed and thus cannot provide the necessary force to easily remove the dull corroded particles from the surface.
• Aside from the blades, they could be cut rather than sharpened.

Glass block:

• Although glass block is somewhat hard by scientific definitions, but it is less hard than stone.

Concept:

Multiple Reflection:

• Multiple reflections are the phenomenon in which the reflected ray of light reflects again by another reflecting surface.
• Multiple images can be formed by the combination of two or more plane mirrors by multiple reflections of light.

Explanation:

• A kaleidoscope is an optical instrument with two or more reflecting surfaces inclined to each other at an angle so that one or more objects on one end of the mirrors are seen as a regular symmetrical pattern when viewed from the other end due to repeated reflection.
• It was invented by Sir David Brewster in 1816.
• It works on the principle of multiple reflections. When the white light hits the surface of the mirror, it gets reflected at an angle such that the angle of incidence is equal to the angle of reflection. Due to these multiple reflections of light, there is a creation of beautiful patterns.

Thus, from the above discussion, it is clear that Kaleidoscope is based on the principle of multiple reflections from three inclined plane mirrors.

The correct option is Electric charges are generated through friction.

Concept:

Electrostatic Force

• The Electrostatic force is the force that acts between two charged particles.
• An object gets positively charged by losing electrons and gets negatively charged by gaining electrons.
• These charges exert forces on each other. The force is attractive if charges are negative and repulsive when charges are positive.
• An object getting charge can induce a charge in other objects and apply electrostatic force on it.

Charging by rubbing 

• Two objects may get charged when they are rubbed against each other.
• If we comb hair, the comb gets charged and so does hair.
• This can be observed by bringing small papers near charge.
• This static charge can be acquired by electrical insulators such as wool.

Explanation:

• When we pull off the sweater, the woollen cloth gets rubbed by our bodies.
• Due to this rubbing transfer of electrons takes place or in other words Electric charges are generated through friction.
• This transfer of charge process causes a crackling sound and sparks are observed.

Additional Information

• Magnetic force: The force by which a magnet attracts iron or other magnetic materials is called magnetic force. An electric current-carrying conductor also applies magnetic force at its nearby.
• Gravitational force: The force acting between two masses by virtue of mass is the gravitational force. Anything falls on earth by the gravitational force of the Earth.
• Muscular force: The force which we apply by our muscles is called muscular force.

• The bird Dodo is an example of Extinct species.

Concept:

• Extinct species refer to those that have no living individual on Earth now.
• Extinction of a species can be caused by various natural and man-made reasons.
• The major causes, referred to as the 'Evil Quartet', include the following:
• Habitat loss & Fragmentation - Many species lose their habitats when forests are cleared or broken up into fragments for human activities.
• Invasion of non-native species - When new species are brought into their habitat from other external habitats.
• Overexploitation - When species are over-harvested for human consumption.
• Co-extinctions - Species living in obligatory associations become extinct together as they are co-dependent.

Important Points

• Dodo was a flightless bird that lived on the island of Mauritius.
• When Portuguese and Dutch sailors landed on this island, the birds were discovered for the first time.
• They started killing these birds for its flesh.
• The sailors used them for food because they were easy source for fresh meat.
• The bird population started decreasing because of this.
• As human settlements increased, the bird's natural habitat was also lost and this led to the ultimate extinction of the bird.
• The last Dodo was killed in 1681.

Additional InformationSome other extinct animals - 

• Quagga - South Africa
• Stellar's Sea Cow - Russia
• Thylacine - Australia
• Passenger Pigeon - North America

The correct option is for welding and cutting metals.

Key Points

• Oxyacetylene torches are used for welding and cutting metals.
• Only an acetylene torch is not able to cut and weld the steel or metal.
• Oxyacetylene is the combination is oxygen and acetylene.
• Both the compounds i.e. oxygen and acetylene cannot be put in the same cylinder.
• Oxygen should be put in one cylinder and acetylene should be put in another cylinder.
• The oxygen and acetylene are used under the pressure and form a needle-point blue flame that can cut and weld metal or steel.
• If the oxygen and acetylene are put in the same cylinder the mixture can be explosive and harmful.

Additional Information

• Microchips are generally known as a chip, integrated circuits (IC), or computer chips.
• It is an electronic circuit consisting of silicon flat pieces.
• Various materials like metal, plastic, paper, ceramic, glass, wood, wax, etc. are used in packaging food items.
• Various cutting and drilling tools are used in various industries like drills, single-point turning tools, fly cutters, shapers, planers, milling cutters, etc.

The correct answer is -Red coloured leaves cannot perform photosynthesis.

Key Points

• Red-leaved plants need a great deal of sunlight to create food.
• Red-leaved plants have large amounts of other pigments namely Carotenoids.
• These pigments are known to absorb some wavelengths of visible light and reflect others.
• All the plants have a combination of several pigments in their leaves.
• The colours we perceive are the ones that are reflected.
• There are several forms of pigments, some of which reflect green light, others orange light, and still others different colours of the spectrum.
• The pigment that gives plants their green hue is the most common and is called chlorophyll a.
• The leaf contains trace quantities of other kinds.
• Carotenoids are yellow/orange in colour.
• Anthocyanins are red/purple in colour.
• Chlorophylls are green in appearance.

Additional Information

• Mode of Nutrition
• It is true all plants are autotrophic.
• They prepare their own food.
• Plants if they have green colour or not can synthesise their own food.
• They utilize sunlight and inorganic material to form organic compounds.
• Algae
• The word algae refer to a broad and varied collection of photosynthetic eukaryotic organisms.
• Algae plants have a large number of unicellular plants.
• Algae are mostly aquatic plants found in both freshwater and salt water.
• Nutrient uptake
• Plants take up a large number of minerals from the soil.
• Plants take up nitrogen, sodium and potassium from the soil.
• Deficiency in the uptake of any one of them results in adverse symptoms.

Concept:

• Wool is obtained from the fleece of animals.
• This wool is in form of thin fibres which are then woven to make clothes.
• Fabrics are made up of yarns and yarns are further made up of fibres.
• Clothes are made out of fabrics.

Explanation:

Shearing:

• Wool is obtained from the hair of sheep or yak.
• Shearing is the process by which hairs are removed from the bodies of wool yielding animals.
• This hair is then processed to make wool.​

The process by which hair is collected from sheep's body to collect wool is called shearing.

Spinning:

• The process of making yarn from fibres is called spinning.
• In this process, fibres from a mass of cotton wool are drawn out and twisted.
• This brings the fibres together to form a yarn.
• A simple device used for spinning is charkha.

Weaving:

• The process of arranging two sets of yarns together to make a fabric is called weaving.
• The weaving of fabric is done on looms.
• The looms are either hand-operated or power-operated.

Ginning:

• Fibres of the cotton ball are separated from the seeds by combing.
• This process is called ginning of cotton.
• Ginning was traditionally done by hand.
• These days, machines are also used for ginning.

The correct answer is Fuse.

Key Points

• Fuse is an electrical safety device  used to protect an electrical or electronic device from over currents.
• The electric fuse is connected to the live wire.
• When the current above the rated value of the fuse flows through the fuse, the heat generated will cause the fuse wire to melt, thereby breaking the connection.
• An electric fuse is a protective device that protects electrical equipment in the circuit by breaking the circuit when there is a short circuit.
• It contains a fuse wire which has a low melting point, it allows normal current to pass through it safely but if there is any short circuit fuse wire can’t withstand the heat produced by that current (infinite current) so it melts and breaks the circuit
• Hence fuse wire used to have a low melting point and high resistance to avoid overload or short circuit.
• Whereas the fuse rating of electrical fuse is the maximum amount of current can pass through it without melting the fuse wire.

Additional Information 

• The material used for fuse elements must be of:
• Low melting point, low ohmic loss.
• High resistivity.
• Low cost and free from detraction.
• The material used for making fuse element has a low melting point such as tin, lead, or zinc.
• A low melting point is, however, available with a high specific resistance metal.
• The material mainly used for fuse elements are tin, lead, silver, copper, zinc, aluminium,  and an alloy of lead and tin.

The correct answer is -Biological Contaminants.

Key Points

• Biological Contaminant
• Generally, biological contamination refers to pollution of biological origin.
• Biological pollutants include bacteria, viruses, animal dander and cat saliva, household dust, mites, cockroaches, and pollen.
• There are several sources of these toxins.
• Excretory products, such as faeces and urine, are also considered biological contaminants.
• If a pollutant originates from a biological source and is harmful to human health, it is termed a biological contaminant.

Additional Information

• Physical pollutants
• Physical pollutants have a major effect on water's appearance or other physical qualities.
• Sediment or inorganic material floating in the water of lakes, rivers, and streams due to soil erosion are examples of physical pollutants.
• Compound pollutants
• Elemental or compound pollutants are chemical contaminants.
• These pollutants may be of natural or anthropogenic origin.
• Chemical pollutants include nitrogen, bleach, salts, pesticides, metals, bacterial toxins, and human or animal medications.
• Radioactive pollutants
• ​Radioactive pollutants are ionizing radiation-emitting chemical elements.
• Radiological pollutants include caesium, plutonium, and uranium, among others.

The correct answer is -Green manure.

Key Points

• Green Manure
• Green manure is a type of soil amendment that involves incorporating crops into the soil in order to improve soil fertility and structure.
• Using Legumes and grasses together can complement each other's growth.
• Green manures add organic matter to the soil, helping to improve soil structure, increase water retention, and reduce soil erosion.
• Green manures can be used to add essential nutrients to the soil, such as nitrogen, phosphorus, and potassium, which are critical for plant growth.
• Farmers can increase their crop yields by using green manures and producing higher-quality crops.
• Green manures are an environmentally friendly way of improving soil fertility, as they require no synthetic fertilizers or pesticides
• They can help to reduce greenhouse gas emissions by sequestering carbon in the soil.

Additional Information

• Crop Rotation
• Crop rotation is a farming practice where different crops are grown in the same field in a specific sequence over a period of time.
• The main purpose of crop rotation is to improve soil fertility and health, as different crops require different nutrients and growing conditions.
• Crop rotation also helps to reduce pest and disease pressure, as pests and diseases that may have built up in the soil from one crop are less likely to affect the next crop in the rotation.
• Rotating crops can also improve water retention and reduce erosion, improving overall crop yields and farm profitability.
• Multiple cropping
• Multiple cropping is a farming method where two or more crops are grown in the same field in a single growing season.
• This farming method allows farmers to maximize land use and increase crop yields while reducing the risk of crop failure.
• Multiple cropping also helps to promote soil health by reducing soil erosion, increasing soil organic matter, and improving soil fertility.
• Transplantation
• Transplantation is the process of transferring a plant from one location to another.
• It is a common agricultural practice used to improve crops' growth and health.
• The method involves digging a young seedling from a nursery bed and transplanting it into a field or garden.
• It allows the plant to grow in a more conducive environment and provides more space for root development.

The correct answer is Spontaneous combustion.

• Spontaneous burning is when a substance catches fire as soon as its temperature reaches the ignition temperature.
• White Phosphorus catches fire at room temperature of 35°C.

Additional Information

• Explosion combustion reaction that takes place suddenly with the evolution of heat light and sound.
• In this case, a large amount of gas is evolved which gets liberated.
• When a cracker is ignited it suddenly reacts and bursts.
• A rapid combustion is a form of combustion in which large amounts of heat and light energy are released.
• This is used in a form of machinery, such as internal combustion engines, and thermobaric weapons.
• The burning of LPG is an example of rapid combustion.

Important Points

• Hydrocarbon fuels can undergo complete combustion or incomplete combustion, depending on the amount of oxygen available.

The correct option is The length of the rubber band increases when it is pulled.

Key Points

• Under the influence of force, the body can change its size, shape, velocity, and direction.
• An item changes shape when force is applied.
• A push or pull that an object experiences as a result of interacting with another item are known as a force.

Example:

• The length of the rubber band increases when it is pulled.
• The seat cushion changes their shape when we sit on them.
• You press a balloon it changes its shape due to force.

The correct option is red litmus blue.

Key Points

• Magnesium combines with oxygen to form magnesium oxide. The aqueous solution of MgO turns red litmus to blue.
• If we dissolve magnesium oxide in water, it produces a basic solution and turns the red litmus paper into blue.
• Magnesium oxide (MgO) is a basic solution.
• If we mix MgO in water, the solution will also become basic in nature due to the presence of Mg(OH)₂.
• When MgO is added to water, there is an increase of hydroxide (OH^-) ions, and form Mg(OH)₂ due to which the solution becomes basic.
• MgO + H₂O → Mg(OH)₂

Additional Information

• The litmus paper is the paper that is able to change color as per the acidity or basicity of the solution.
• It is used to measure the acidity and basicity of the solution.
• It can also be used as a pH indicator.
• If the solution is acidic the blue litmus paper turns red.
• If the solution is basic in nature the red litmus paper turns blue.
• The purple litmus paper is neutral in nature.

The correct answer is Fungi

Key Points 

• An organism that decomposes organic material is called a decomposer.
• The decomposer breaks down the dead organic material.
• Fungi and bacteria are decomposers that obtain their nutrients from a dead plant or animal material.
• Decomposers break down the cells of organisms into simpler substances, which become organic nutrients available to the ecosystem.

Additional Information

• A plant that is not green and does not have leaves or flowers, or that is like a wet powder and grows on old wood or food, walls, etc. is called fungi.
• Fungi are eukaryotic organisms that include microorganisms such as yeast, molds, and mushrooms.
• Fungi are non-vascular, and they do not contain chloroplast, which leads to the absence of photosynthesis.

The correct answer is -wall of the Uterus.

Key Points

• Fertilization
• Fertilization is the process of combining genetic material from a male and female gamete to create a zygote.
• This process typically occurs in the fallopian tube and involves the sperm penetrating the egg.
• If the sperm and egg successfully combine, the resulting zygote will travel down the fallopian tube.
• The zygote eventually embeds itself in the wall of the uterus, beginning the process of embryonic development.
• Embeddement on the wall of the uterus
• The uterus wall provides a suitable environment for the embryo to grow and develop into a fetus.
• The embryo receives essential nutrients and oxygen from the mother's blood supply.
• The implantation of the fertilized egg in the uterus is a crucial step in the formation of a successful pregnancy.

Additional Information

• Umbilical cord
• After fertilization, the fertilized egg begins to divide and form an embryo.
• As the embryo grows, it attaches itself to the wall of the uterus via the umbilical cord
• It is the lifeline between the mother and the fetus.
• The umbilical cord provides essential nutrients and oxygen from the mother to the developing fetus.
• It also removes waste products from the fetus.
• Cervix
• ​After fertilization, the cervix plays a crucial role in protecting the growing fetus and supporting a healthy pregnancy.
• It helps to keep the uterus closed, preventing any potential harm to the developing baby.
• It also produces mucus to maintain a suitable environment for the fetus to grow.
• Vagina
• ​The vagina is not directly affected by the fertilization process.
• It may experience changes later on during pregnancy.
• These changes can include increased blood flow, hormonal changes, and thickening of the vaginal walls.

The correct option is Teflon has a high melting point & prevents materials from sticking to it and getting burnt.

Key Points 

• Teflon coatings are widely used in pans & other cookware because Teflon has a high melting point & prevents materials from sticking to it and getting burnt.
• Teflon is a kind of non-stick coating used for various purposes.
• Teflon has the chemical name polytetrafluoroethylene (PTFE) which is a synthetic chemical.
• It generates a non-stick surface, is able to reduce friction, and is waterproof in nature.
• Teflon is a unique type of plastic and is able to tolerate extreme temperatures.
• Teflon is used as an inner coating in non-stick cookware.

Additional Information

• Teflon was discovered by Roy Plunkett who is an American chemist.
• The first non-stick cookware coated with Teflon was discovered by DuPont.
• Teflon is a solid white color compound at room temperature.
• It has a melting point of 600 K and a density of 2.2 g/cm³.
• It has good resistance capacity towards heat and low temperatures.
• It has an anti-adhesion property due to which it is used in non-stick cookware.

The correct answer is Greenland.

Key Points

• Rainforests thrive on every continent except Antarctica.
• The largest rainforests on Earth surround the Amazon River in South America and the Congo River in Africa.
• Tropical rainforests are seen in India, Africa, and Indonesia but are not found in Greenland.

Additional Information

• These forests are restricted to heavy rainfall areas of the Western Ghats and the island groups of Lakshadweep, Andaman, and Nicobar, upper parts of Assam, and the Tamil Nadu coast.
• They are at their best in areas having more than 200 cm of rainfall with a short dry season.
• The trees reach great heights up to 60 meters or even above.
• Since the region is warm and wet throughout the year, it has luxuriant vegetation of all kinds — trees, shrubs, and creepers giving it a multilayered structure.

The correct answer is -Testosterone.

Key Points

• Testosterone
• Testosterone is a male hormone that plays a significant role in developing male characteristics.
• It is produced in the testes.
• The hypothalamus and pituitary gland regulate it.
• The physical changes brought by testosterone include:
• Increased muscle mass and strength
• Development of facial and body hair
• Deepening of the voice
• Increased bone density
• Widening of the shoulders
• Narrowing of the hips.

Additional Information

• Insulin
• Insulin is a hormone produced by the pancreas
• It regulates blood sugar levels in the body.
• It plays an important role in metabolism and energy storage.
• When insulin is released into the bloodstream, it helps glucose enter cells, which can be used for energy.
• Insulin also promotes the storage of glucose in the form of glycogen and fat.
• Thyroxin
• ​A hormone produced by the thyroid gland.
• Regulates the body's metabolism by increasing the oxygen consumption of cells
• Thyroxin also helps maintain healthy skin, hair, and nail growth.
• It plays a role in regulating body temperature and maintaining proper heart rate.
• Estrogen
• Estrogen is a hormone that plays a crucial role in regulating various physiological processes in the body.
• It is responsible for the development of female secondary sexual characteristics, such as
• breast development
• widening of the hips
• the regulation of the menstrual cycle.

The correct option is Sea water shows more deflection than tap water.

Key Points

• Compared to drinking water, seawater has a significantly higher concentration of dissolved salts.
• As a result, seawater conducts electricity more readily.
• In the wire, it results in a stronger magnetic field.
• As a result, in the presence of seawater, the compass needle deflects more.

Additional Information

• The larger magnetic field created by the cable due to the increased electric current flowing through the water causes the compass needle to deviate more.

The correct solution is The brain of the cell.

Key Points

• The brain of a cell
• The brain of a cell is also known as the nucleus.
• It plays a crucial role in controlling the activities of a cell.
• It contains genetic material in the form of DNA.
• It helps in directing the functions of the cell.
• The nucleus also acts as the control center for cell division, gene expression, and regulation of metabolism.
• The cell's brain is protected by a nuclear envelope and is responsible for transmitting information to the rest of the cell through various signaling pathways.
• The nucleus acts as the central nervous system of a cell, providing vital control and regulation.

Additional Information

• Mitochondria.
• The powerhouses of the cell are known as the mitochondria.
• These organelles generate the majority of cellular energy in the form of ATP through cellular respiration.
• The number of mitochondria in a cell can vary depending on the energy demands of that particular cell.
• Plastids
• Plastids are the "kitchens" of the cell, responsible for producing and storing food and energy.
• They contain chlorophyll, the pigment responsible for capturing sunlight during photosynthesis.
• It plays a crucial role in providing energy for the cell.
• Plastids are found in plant cells and are divided into three types:
• chloroplasts,
• leucoplasts, and
• chromoplasts
• Suicidal bags
• Lysosomes are known as the "suicidal bags" of a cell.
• They contain hydrolytic enzymes that break down cellular waste and harmful substances.
• They play a crucial role in maintaining the health of a cell by removing any harmful material and preserving its overall functioning.
• By breaking down and digesting unwanted material.
• Lysosomes ensure that the cell remains functional and healthy.

The correct option is 10 years.

Key Points

• 10 years means One decade.
• 100 years means One Century.
• 10 decades means 100 years which is One Century.
• 1000 years means a millennium.
• 500 years means 5 Centuries.

The correct option is Plane mirror.

Key Points

• The flat steel plate's outside part act as a plane mirror.
• A flat steel plate can create an image that is virtual, upright, and the same size as the object, much like a plane mirror.

Additional Information

Plane Mirror: 

• The plane mirror is a flat surface that, when the front and back are switched, gives a straight-on visual representation of an actual object.
• In a plane mirror, the phenomenon is known as "lateral inversion".
• It causes an object's left side to appear as the image's right side and vice versa.

​Concave mirrors: 

• These are spherical mirrors with a reflecting inner surface.

Convex mirrors:

• These are spherical mirrors with a reflecting surface on the outside.

The correct answer is - Virus.

Key Points

• Swine flu
• It is also known as hog cholera or swine influenza.
• It is an acute respiratory disease that affects pigs.
• The main cause of swine flu is the influenza virus.
• The virus is highly contagious and can spread quickly among pigs.
• The disease is not caused by bacteria, fungi, or protozoa,
• It is caused by a specific type of influenza virus known as H1N1.
• Swine flu can result in high mortality rates in pig populations.
• The symptoms of swine flu in pigs include
• fever,
• coughing,
• sneezing, and
• nasal discharge.

The correct option is Copper is a better conductor of heat.

Key Points

• The stainless steel utensils have copper bottoms because copper is a better conductor of heat.
• Stainless steel cookware generally comes with copper bottoms.
• Copper is a good conductor of heat.
• Copper is able to heat soon as compared to only steel.
• Copper has good conductivity than steel and is able to hot quickly.
• Due to this reason, stainless cookware mostly comes with copper bottoms.

Additional Information

• Copper is an element that has the chemical formula Cu.
• It comes under group 11 of the periodic table.
• It has the atomic number 29.
• Copper has a shiny or lustrous brown color.
• Copper has the property to be ductile and malleable.
• It is a good conductor of heat and electricity.
• Copper is used in metallurgy, electric wires, etc.

The correct option is in Road surfacing.

Key Points

• The fraction of Bitumen obtained from petroleum refining is used in road surfacing.
• Bitumen is a type of hydrocarbon and comes under secondary hydrocarbons
• Bitumen can be obtained from crude oil distillation.
• It is a low-grade crude oil and has heavy hydrocarbons.
• It is a semi-solid hydrocarbon compound.
• Bitumen can be used in building construction sites, for roof proofing, for road surfacing, etc.

​ 

Additional Information

• Wax is used in making candles.
• Aviation kerosene is used as an aviation fuel. It is also known as QAV.
• Aviation gasoline, Biokerosene, Jet fuel, etc are also known to be used as aviation fuels.
• The substance that reduces the friction between body parts are called lubricants.

भूकंप के प्रकोप से अनेक लोगों की जानें गई।शुद्ध वाक्य का उदाहरण है।

अन्य विकल्प निरर्थक है।

Confusion Points

• भूकंप के प्रकोप से अनेकों लोगों की जानें गई - अशुद्ध वाक्य
• अनेक शब्द स्वयं में बहुवचन है इसका बहुवचन अनेको नही होगा।

Key Points 

• वाक्य शुद्धि - लिखने एवं बोलने में इस बात का ध्यान रखना कि जो कुछ भी लिखा या कहा जा रहा है वह बिल्कुल सार्थक एवं व्याकरण के नियमानुसार शुद्ध हो।
• उदाहरण - मुझे यह अच्छा नही लगता।

Important Points

• भूकंप के प्रकोप से अनेकों लोगों की जानें गई इस वाक्य में वचन सम्बन्धी अशुद्धि है।
• शुद्ध वाक्य - भूकंप के प्रकोप से अनेक लोगों की जानें गई।

Additional Informationवाक्य शुद्धि के प्रकार - वाक्य शुद्धि के निम्नलिखित प्रकार है। 

परीक्षाभवन तत्पुरुष समास का उदाहरण है। 

Confusion Points

• परीक्षाभवन में सम्प्रदान तत्पुरुष समास है।
• परीक्षाभवन = परीक्षा के लिए भवन

Key Points

• सम्प्रदान तत्पुरुष समास - जिस तत्पुरुष समास में " के लिए" परसर्ग का प्रयोग हुआ हो उसे सम्प्रदान तत्पुरुष समास कहते है।
• उदाहरण - रसोईघर = रसोई के लिए घर, यज्ञशाला= यज्ञ के लिए शाला आदि।

Important Points

तत्पुरुष समास - जिस समास में दूसरा पद प्रधान हो। 

अन्य विकल्पों का विश्लेषण -

Additional Informationअन्य विकल्प - 

'पित्रनुमति' का संधि विच्छेद है- पितृ + अनुमति है।

Confusion Points

• पित्रनुमति का संधि विच्छेद पितृ+अनुमति होता है।
• 'पित्रनुमति' शब्द में 'ऋ + अ = र' का मेल हो रहा है इसलिए यहां यण स्वर संधि है।

Key Points

• यण स्वर संधि - इ, ई, उ, ऊ या ऋ का मेल यदि असमान स्वर से हो तो इ, ई का 'य'; उ, ऊ का 'व' और ऋ का 'र' हो जाता है।
• जैसे - यदि + अपि (इ + अ) = यद्यपि, अनु + एषण = अन्वेषण।
• ​अन्य विकल्प निरर्थक है।

Important Pointsसंधि-दो शब्दों के मेल से जो विकार (परिवर्तन) होता है उसे संधि कहते हैं। संधि के तीन प्रकार हैं -

Additional Information

• दीर्घ स्वर संधि - दो सवर्ण, ह्रस्व या दीर्घ, स्वरों के मेल होने पर दीर्घ स्वर बन जाता है।
• जैसे – शिव + आलय (अ + आ) = शिवालय, गिरि + इन्द्र (इ + इ) = गिरीन्द्र।
• गुण स्वर संधि - अ, आ के साथ इ, ई का मेल होने पर 'ए'; उ, ऊ का मेल होने पर 'ओ'; तथा ऋ का मेल होने पर 'अर्' हो जाता है।
• जैसे – देव + इन्द्र (अ + इ) = देवेन्द्र
• वृद्धि स्वर संधि - अ, आ का मेल ए, ऐ के साथ होने पर 'ऐ' तथा ओ, औ के साथ होने पर 'औ' में परिवर्तित हो जाता है।
• जैसे – एक + एक (अ + ए) = एकैक, परम + ओजस्वी (अ + ओ) = परमौजस्वी।
• अयादि स्वर संधि- यदि ए, ऐ, ओ, औ के साथ कोई अन्य स्वर हो तो ए का अय, ऐ का आय, ओ का अव, औ का आव हो जाता है।
• जैसे – ने + अन = नयन (ए + अ = अय)

संस्कृत भाषा के ऐसे शब्द, जिनका हिन्दी भाषा में प्रयोग करने पर रूप परिवर्तित नहीं होता, तत्सम शब्द  कहलाते हैं।

Key Points

• संस्कृत भाषा के शब्द जिनकी हिन्दी भाषा में प्रयोग करने पर रुप परिवर्तित नहीं होता वे तत्सम शब्द कहलाते हैं।
• उदाहरण - आम्र, अग्नि, अमूल्य, क्षेत्र, अज्ञान, अन्धकार, चंद्र आदि।

Important Points​ 

Additional Information

• देशज शब्द: वे शब्द जिनकी उत्पत्ति के मूल का पता न हो परन्तु वे प्रचलन में हों। ऐसे शब्द देशज शब्द कहलाते हैं। ये शब्द आम तौर पर क्षेत्रीय भाषा में प्रयोग किये जाते हैं। 
• उदाहरण - लोटा, कटोरा, डोंगा, डिबिया आदि।
• विदेशज शब्द: विदेशी भाषाओं से हिंदी में आये शब्दों को विदेशी शब्द कहा जाता है। इन विदेशी भाषाओं में मुख्यतः अरबी, फारसी, तुर्की, अंग्रेजी व पुर्तगाली शामिल है।      ​
• **उदाहरण -**अदा, अजब, अजीब, अमीर आदि।
• तद्भव शब्द: तत्सम शब्दों में समय और परिस्थितियों के कारण कुछ परिवर्तन होने से जो शब्द बने हैं उन्हें तद्भव कहते हैं।                                                                      
• उदाहरण - मुख से मुँह, ग्राम से गाँव, दुग्ध से दूध आदि।

'पलंगड़ी' में ड़ी प्रत्यय है।

Key Points

• पलंग + ड़ी = 'पलंगड़ी'
• प्रत्यय – वे शब्दांश जो किसी शब्द या धातु के अंत में जुड़कर उसके अर्थ को प्रभावित कर देते हैं उन्हें प्रत्यय कहते हैं।

Important Pointsअन्य उदाहरण -

दिए गए विकल्पों में से संप्रदान कारक का विभक्ति चिन्ह "के लिए" है।

Key Points

• सम्प्रदान कारक का अर्थ होता है – देना।
• जिसके लिए कर्ता काम कर्ता है उसे सम्प्रदान कारक कहते हैं।
• सम्प्रदान कारक के विभक्ति चिन्ह के लिए और को होता है।

उदाहरण - 

• हम पढ़ने के लिए स्कूल जाते हैं।
• माँ बच्चे को खिलौना देती है।

Additional Information

• संज्ञा या सर्वनाम के जिस रूप से उसका सम्बन्ध वाक्य के किसी दूसरे शब्द के साथ जाना जाए, उसे कारक कहते हैं।
• वाक्य में प्रयुक्त शब्द आपस में सम्बद्ध होते हैं।
• क्रिया के साथ संज्ञा का सीधा सम्बन्ध ही कारक है।
• कारक को प्रकट करने के लिये संज्ञा और सर्वनाम के साथ जो चिन्ह लगाये जाते हैं, उन्हें विभक्तियाँ कहते हैं।
• जैसे - पेड  पर फल लगते हैं।
• इस वाक्य में पेड  कारकीय पद हैं और ’पर’ कारक सूचक चिन्ह अथवा विभक्ति है।

हिन्दी में ’आठ कारक’ माने गए हैं - 

दिए गए विकल्पों में से  सामासिक पद "अष्टध्यायी" के सही विग्रह - ​आठ अध्यायों का समाहार

Key Points

• अष्टाध्यायी शब्द में द्विगु समास है।
• द्विगु समास - वह समास जिसका पूर्व पद संख्यावाचक विशेषण होता है,
• तथा समस्तपद समाहार या समूह का बोध कराए, उसे द्विगु समास कहते हैं।

Additional Information

• अलग अर्थ रखने वाले दो शब्दों या पदों (पूर्वपद तथा उत्तरपद) के मेल से बना तीसरा नया शब्द या पद समास या समस्त पद कहलाता है।
• सामासिक शब्दों के बिच जों संबंध है उसे स्पष्ट करना समास विग्रह कहलाता हैं।
• जैसे - की विश्वविजय का समास विग्रह “विश्व को जितने वाला” होता हैं।

समास में 6 भेद होते हैं- 

दिए गए विकल्पों में से 'लड़ाकू' में "आकू" प्रत्यय है। 

Key Points

• यहाँ पर मूल शब्द ‘लड़’ एक क्रिया है।
• जिसमें कृत प्रत्यय ‘आकू’ जुडने से बना शब्द ‘लड़ाकू’ कृदन्त शब्द कहा जाएगा।

Additional Information

• जो शब्दांश शब्दों के अंत में विशेषता या परिवर्तन ला देते हैं, वे प्रत्यय कहलाते हैं।

प्रत्यय के दो भेद हैं-

कृत् प्रत्यय- 

• क्रिया या धातु के अन्त में प्रयुक्त होनेवाले प्रत्ययों को 'कृत्' प्रत्यय कहते है,
• और उनके मेल से बने शब्द को 'कृदन्त' कहते है।
• जैसे- लेख् + अक = लेखक। यहाँ अक कृत् प्रत्यय है, तथा लेखक कृदंत शब्द है।

तद्धित प्रत्यय-

• धातुओं को छोड़कर अन्य शब्दों में लगनेवाले प्रत्ययों को तद्धित कहते हैं।
• जब संज्ञा, सर्वनाम, विशेषण के अंत में प्रत्यय लगते हैं, उन शब्दों को तद्धित प्रत्यय कहते हैं।
• तद्धित प्रत्यय से बने शब्द तद्धितांत शब्द कहलाते हैं।
• जैसे- सेठ + आनी = सेठानी। यहाँ आनी तद्धित प्रत्यय हैं तथा सेठानी तद्धितांत शब्द है।

दिए गए विकल्पों में से शुद्ध वाक्य होगा - पहाड़ों में अनेक दर्शनीय स्थल हैं।।

Key Points

• पहाड़ों में कई दर्शनीय स्थल देखने योग्य हैं। -शब्द चयन सम्बन्धी अशुद्धि
• पहाड़ों में देखने योग्य अनेक दर्शनीय स्थल हैं।- पदक्रम संबंधी अशुद्धि
• अनेक दर्शनीय स्थल देखने योग्य हैं पहाड़ों में।- पदक्रम संबंधी अशुद्धि

Additional Information

• व्याकरण के नियमानुसार वाक्य में आई अशुद्धि को दूर कर उसे पुनः शुद्ध रूप में लिखना ही वाक्य शुद्धि कहलाता है |
• मुख्य रूप से वाक्य में अशुद्धि के कारण हैं - वाक्य में अनावश्यक शब्द प्रयोग से,
• अनुपयुक्त शब्द के प्रयुक्त होने से, सही क्रम या अन्विति न होने से, लिंग, वचन, कारक का सही प्रयोग नहीं होने से
• एवं सही सर्वनाम एवं क्रिया का प्रयोग न होने से।

दिए गए विकल्पों में से "बेटा-बेटी" द्वन्द समास का उदाहरण है।

• बेटा-बेटी का समास-विग्रह -  बेटा और बेटी

Key Points

• जिस सामासिक शब्द के दोनों ही पद प्रधान होते हैं।
• और उनका विग्रह करने पर “और”, “अथवा”, “या” जैसे शब्द लगते हो तो उसे द्वंद्व समास कहते हैं।
• इसमें, सामासिक शब्दों के दो पदों के बीच मे (-)योजक चिन्ह आता हैं।
• जैसे- राम-श्याम. इसका विग्रह होगा- राम और श्याम।

Additional Information

• अलग अर्थ रखने वाले दो शब्दों या पदों (पूर्वपद तथा उत्तरपद) के मेल से बना तीसरा नया शब्द,
• या पद समास या समस्त पद कहलाता है।
• सामासिक शब्दों के बिच जों संबंध है उसे स्पष्ट करना समास विग्रह कहलाता हैं।
• जैसे - की विश्वविजय का समास विग्रह “विश्व को जितने वाला” होता हैं।

समास में 6 भेद होते हैं-

दिए गए विकल्पों में से शुद्ध वाक्य होगा - यह भवन उससे लघुत्तर है।

Key Points

• वाक्य में लघुत्तम शब्द के स्थान पर लघुत्तर शब्द उचित है  ।
• लघुत्तम शब्द का अर्थ -  सबसे छोटा।
• लघुत्तर शब्द का अर्थ - संक्षिप्त, छोटा।

Additional Information

• वाक्य सम्प्रेषण की सबसे महत्वपूर्ण और सार्थक इकाई होती है।
• अतः वाक्यगत अशुद्धियाँ को शुद्ध रूप में लिखना सम्प्रेषण को अधिक सरल बनाता है।
• वाक्य में, संज्ञा, सर्वनाम, लिंग, वचन, क्रिया-विशेषण, क्रिया, विशेषण आदि संबंधी अशुद्धियाँ हो सकती हैं।

शासन की ओर से किसी व्यक्ति को या एक विभाग से दूसरे विभाग को भेजे गये पत्र को "सरकारी पत्र" कहा जाता है। 

Key Points

• शासन द्वारा जो पत्र उच्चतर अधिकारियों जैसे भारत सरकार अथवा समकक्ष अधिकारियों,
• जैसे अन्य राज्य सरकारों, महालेखाकार, लोक सेवा आयोग आदि को भेजे जाते हैं, उन्हें शासकीय पत्र या सरकारी पत्र कहते हैं।
• सरकार के कामकाज से संबंधित पत्र सरकारी पत्र या शासकीय पत्र कहलाते हैं।

Additional Information

दिए गए विकल्पों में से 'मात्रानंद' का संधि विच्छेद "मातृ + आनंद" है।

Key Points

• उपर्युक्त मात्रानंद शब्द में ऋ + आ= रा  का मेल होकर संधि शब्द युक्त शब्द मात्रानंद बना है।
• चूँकि इसमें ऋ + आ= रा  का मेल हुआ है अत: संधि के नियम के अनुसार मात्रानंद में यण संधि होती है।
• मात रा नन्द (‘त’ ‘रा’ से मिलकर ‘त्रा’ बना) शब्द हुआ – मात्रानन्द
• यण संधि- यदि इ/ई, उ/ऊ और ऋ के बाद भिन्न स्वर आए तो इ/ई का ‘य’ उ/ऊ का ‘व’ और ऋ का ‘र’ हो जाता है।

Important Points

• दो वर्णों के मेल से होने वाले विकार को संधि कहते हैं।
• दो शब्दों के मेल से बने शब्द को पुनः अलग अलग करने को संधि विच्छेद कहते हैं।

संधि के तीन प्रकार होते हैं-

Additional Informationस्वर संधि के पांच प्रकार होते हैं-

दिए गए विकल्पों में से 'दांत काटी रोटी' मुहावरे का अर्थ "घनिष्ठ मित्रता" है। 

Key Points

• 'दांत काटी रोटी' मुहावरे का अर्थ है- घनिष्ठ मित्रता
• वाक्य प्रयोग - कृष्ण और सुदामा में दांत काटी रोटी थी।

Additional Information

• मुहावरा शब्द एक अरबी शब्द है जिसका अर्थ होता है–अभ्यास करना।
• मुहावरे वाक्य के अंश होते हैं।
• मुहावरों से सामान्य अर्थ नहीं बल्कि, विशेष अर्थ निकलता है।
• इनके प्रयोग से भाषा में सरसता व रोचकता आ जाती है।

कुछ मुहावरे -

दिए गए विकल्पों में से नयन की ठीक संधि  "ने + अन" है। 

Key Points

• 'नयन' शब्द में 'अयादि संधि' है।
• ने + अन = नयन  (ए + अ = अय )
• जब ए,ऐ,ओ,औ के साथ कोई अन्य स्वर हो तो ” ए- अय “, ” ऐ- आय”, “ओ- अव ” , “औ- आव”  मैं हो जाता है।
• य, व् से पहले व्यंजन पर अ, आ की मात्रा हो तो अयादि संधि हो सकती है,
• लेकिन अगर और कोई विच्छेद न निकलता हो तो + के बाद वाले भाग को वैसा का वैसा लिखना होगा।
• उसे अयादि संधि कहते हैं।

Important Points

• दो वर्णों के मेल से होने वाले विकार को संधि कहते हैं।
• दो शब्दों के मेल से बने शब्द को पुनः अलग अलग करने को संधि विच्छेद कहते हैं।

संधि के तीन प्रकार होते हैं- 

Additional Information

स्वर संधि के पांच प्रकार होते हैं- 

तुलसीदास ने ‘रामचरितमानस'  "अवधी" भाषा में लिखी थी।

Key Points

• रामचरितमानस अवधी भाषा में गोस्वामी तुलसीदास द्वारा 16 वीं सदी में रचित प्रसिद्ध ग्रन्थ है।
• इस ग्रन्थ को अवधी साहित्य (हिंदी साहित्य) की एक महान कृति माना जाता है।
• अवध क्षेत्र की भाषा अवधी कहलाती है, जो हिन्दी की एक उपभाषा है।
• अवधी का प्राचीन साहित्य बड़ा संपन्न है। इसमें भक्ति काव्य और प्रेमाख्यान काव्य दोनों का विकास हुआ।
• रचनाकार - सूफ़ी कवि-  मुल्ला दाउद ('चंदायन'), जायसी ('पद्मावत'), क़ुत्बन ('मृगावती'), उसमान ('चित्रावली')।

Additional Information

अपने साधारण अर्थ को छोड़कर विशेष अर्थ प्रकट करने वाले वाक्यांश "मुहावरे" कहलाते हैं।

Key Points

• ‘मुहावरा’ शब्द अरबी भाषा का है जिसका अर्थ है ‘अभ्यास होना’ या आदी होना’।
• मुहावरा एक ऐसा वाक्य होता है जो वाक्य की रचना करने पर अपना एक अलग अर्थ या विशेष अर्थ प्रकट करता है।
• इनका प्रयोग करने से भाषा,आकर्षक, प्रभावपूर्ण तथा रोचक बन जाती है।

उदाहरण - 

Additional Information

दिए गए विकल्पों में से "स्वयँ" निजवाचक सर्वनाम का उदाहरण है। 

Key Points

• जो सर्वनाम तीनों पुरूषों (उत्तम, मध्यम और अन्य) में निजत्व का बोध कराता है,
• उसे निजवाचक सर्वनाम कहते हैं।
• जैसे- मैं खुद लिख लूँगा। तुम अपने आप चले जाना। वह स्वयँ गाडी चला सकती है।
• उपर्युक्त वाक्यों में खुद, अपने आप और स्वयँ शब्द निजवाचक सर्वनाम हैं।

Additional Information

• संज्ञा के स्थान पर आने वाले शब्दों को सर्वनाम कहते हैं।
• हिंदी के मूल सर्वनाम 11 होते हैं- मैं, वह, क्या, तू , जो, कोई, आप, सो, कुछ, यह, कौन।

सर्वनाम के 6 भेद होते हैं- 

दिए गए विकल्पों में से 'मोहन ने खाना नहीं खाया, "निषेध वाचक" वाक्य है। 

Key Points

• निषेधवाचक वाक्य - जिससे किसी बात के न होने का बोध होता है।
• जैसे - मैंने पुस्तक नहीं पढ़ी।

Additional Information

अर्थ की दृष्टि से वाक्य 8 प्रकार के होते हैं-

दिए गए विकल्पों में से "निष्कलुष" शब्द कलुष का विलोम शब्द है। 

Key Points

• कलुष शब्द का अर्थ है - अपवित्रता।
• निष्कलुष शब्द का अर्थ है - पवित्रता।

Additional Information

• जो शब्द किसी दूसरे शब्द का उल्टा अर्थ बताते हैं,
• उन्हें विलोम शब्द या विपरीतार्थक शब्द या विरुद्धार्थी शब्द कहते है।

उदाहरण - 

'माता - पिता का आशीर्वाद लेते हुए जीवन पथ पर बढ़ते चलें' रेखांकित शब्द में "द्वंद्व समास" समास है।

Key Points

• माता -पिता शब्द में द्वंद्व समास है।
• समास-विग्रह  - माता और पिता
• जिस सामासिक शब्द के दोनों ही पद प्रधान होते हैं और उनका विग्रह करने पर “और”, “अथवा”, “या” जैसे शब्द लगते हो,
• उसे द्वंद्व समास कहते हैं. इसमें, सामासिक शब्दों के दो पदों के बीच मे (- ) योजक चिन्ह आता हैं।
• जैसे - दाल-चावल = दाल और चावल

Additional Information

• अलग अर्थ रखने वाले दो शब्दों या पदों (पूर्वपद तथा उत्तरपद) के मेल से बना तीसरा नया शब्द या पद समास या समस्त पद कहलाता है।
• सामासिक शब्दों के बिच जों संबंध है उसे स्पष्ट करना समास विग्रह कहलाता हैं।
• जैसे - की विश्वविजय का समास विग्रह “विश्व को जितने वाला” होता हैं।

समास में 6 भेद होते हैं- 

दिए गए विकल्पों में से "स्म्रति" शब्द में अशुद्ध वर्तनी है। 

Key Points

• स्म्रति शब्द कि शुद्ध वर्तनी है - स्मृति
• शब्दों के ठीक-ठीक लिखने की ढंग को वर्तनी कहा जाता है।
• हिंदी में इसे अक्षरी भी कहा जाता है।
• उर्दू में इसे हिज्जे और अंग्रेजी में स्पेलिंग कहा जाता है।

Important Points

• स्मृति का शाब्दिक अर्थ है - याद, स्मरण, किसी चीज को याद रखना।
• स्वयंभू का शाब्दिक अर्थ  है - पृथ्वी या भूमि से स्वयं ही उत्पन्न।
• स्वच्छन्द ​का शाब्दिक अर्थ है - जो किसी दूसरे के नियंत्रण में न हो और अपनी ही इन्छा के अनुसार सब कार्य करे ।

Additional Informationअशुद्ध और शुद्ध वर्तनी के उदाहरण - 

दिए गए विकल्पों में से "निराहार" शब्द का सही संधि विच्छेद "नि: + आहार" है। 

Key Points

• निराहार शब्द का संधि विच्छेद नि: + आहार ( विसर्ग संधि )
• जब  विसर्ग के साथ स्वर या व्यंजन आ जाए तब जो परिवर्तन होता है ,वह विसर्ग संधि कहलाता है।
• यदि विसर्ग के पहले ‘अ’ और ‘आ’ को छोड़कर कोई दूसरा स्वर आए और विसर्ग के बाद कोई स्वर हो,
• या किसी वर्ग का तीसरा, चौथा या पाँचवाँ वर्ण हो या ‘य’, ‘र’, ‘ल’, ‘व’, ‘ह’ में से कोई वर्ण हो,
• तो विसर्ग के स्थान में ‘र्’ हो जाता है।

 जैसे- 

• नि: + धन = निर्धन
• दु: + आशा = दुराशा

Additional Information

• दो वर्णों के मेल से होने वाले विकार को संधि कहते हैं।
• दो शब्दों के मेल से बने शब्द को पुनः अलग अलग करने को संधि विच्छेद कहते हैं।
• उदाहरण- हिमालय- हिम+आलय

संधि के तीन प्रकार है-

दिए गए विकल्पों में से "उद्यत" शब्द 'चतुर' का पर्यायवाची नहीं है।

Key Points

• 'चतुर' का पर्यायवाची - विज्ञ, निपुण, नागर, पटु, कुशल, दक्ष, प्रवीण, योग्य।
• उद्यत का पर्यायवाची - तत्पर, कटिबद्ध, मुस्तैद, तैयार  आदि ।

Additional Information

• समान अर्थ प्रदान करने वाले शब्द पर्यायवाची शब्द अथवा समानार्थक शब्द कहलाते हैं।

कुछ पर्यायवाची शब्द -

• अतिथि- मेहमान ,पाहुन ,आगंतुक, अभ्यागत।
• विष- गर्ल, कालकूट, जहर, हलाहल।
• लज्जा- संकोच, लाज, ह्या, शर्म।
• रात्रि- राका, निशा, रजनी, यामिनी, विभावरी।
• युद्ध- रण, समर, संग्राम, जंग, लड़ाई।
• भय- त्रास, भीति, डर, खौफ, आतंक।
• बगीचा- बाग, उपवन, वाटिका ,उद्यान, निकुंज।
• फूल- पुष्प, कुसुम,पुहुप, सुमन, प्रसून।
• पथ- मग, मार्ग, राह, पंथ, रास्ता।
• तरुण- युवा,जवान, युवक।

दिए गए विकल्पों में से "प्रतिवर्ष" शब्द में  अव्ययी समास है। 

• प्रतिवर्ष समस्तपद ‘प्रति’ और ‘वर्ष’ के योग से बना है।
• इसका पहला पद (पूर्वपद) ‘प्रति’ अव्यय है।
• प्रतिवर्ष का समास-विग्रह -  हर वर्ष।
• जिस समास का पहला पद कोई अव्यय (अविकारी शब्द) होता है, उस समास को अव्ययीभाव समास कहते हैं।

Key Points

• नवरत्न शब्द में द्विगु समास है।
• नवरत्न का समास-विग्रह - नव रत्नों का समाहार
• विषधर शब्द में बहुव्रीहि समास है।
• विषधर का समास-विग्रह- विष को धारण करता है जो - (सर्प)
• राजा रानी में बीच योजक चिन्ह के प्रयोग होने पर द्वंद्व समास होगा।
• राजा- रानी का समास विग्रह  - राजा और रानी

Additional Information

• अलग अर्थ रखने वाले दो शब्दों या पदों (पूर्वपद तथा उत्तरपद) के मेल से बना तीसरा नया शब्द या पद समास या समस्त पद कहलाता है।
• सामासिक शब्दों के बिच जों संबंध है उसे स्पष्ट करना समास विग्रह कहलाता हैं।
• जैसे - की विश्वविजय का समास विग्रह “विश्व को जितने वाला” होता हैं।

समास में 6 भेद होते हैं-

Given:

The arithmetic mean of a set of 20 values is 76.

Concept used: 

New mean = Old mean divided by common number, which divides all the numbers.

Average = Sum of observation / Number of observations

Calculation:

⇒ New mean = \(76 \over4 \)

⇒ New mean = 19

∴ If each of the 20 values is divided by 4, then its new mean is 19.

Given:

An iron pipe 10 cm long has external diameter of 12 cm.

Thickness of the pipe is 2 cm. 

Concept used: 

TSA = 2πh(r + R) + 2π (R² - r²)

Calculation:

R = 6 cm

r = 4 cm

h = 10 cm

⇒ TSA = 2πh(r + R) + 2π (R - r)

⇒ 20π (6 + 4) + 2π (36 - 16)

⇒ 200π + 40π

⇒ 240π

∴ The total surface area (in cm2) of the pipe is 240π cm²

Given:

A circle is inscribed in a triangle ABC having sides AB = 8 cm, BC = 4 cm, CA = 6 cm, touching the circle at D, E and F respectively.

Concept used: 

Tangents drawn from same external points are equal in length.

Calculation:

⇒ BD = BE = m

⇒ EC = CF = n

⇒ AD = AF = p

⇒ m + n = 4   

⇒ m = 4 - n   → (1)

⇒ n + p = 6

⇒ p = 6 - n    → (2)

⇒ m + p = 8    → (3)

⇒ 4 - n + 6 - n = 8

⇒ 10 - 2n = 8

⇒ n = 1

⇒ m = 3

⇒ p = 5

∴ The lengths of DB, CE and AF are 3 cm, 1 cm, 5 cm, respectively.

Given:

The number \(0 . \bar{1}=\frac{1}{9}\), then we have to find 0.999.. in p/q form

Concept used: 

The digits which have a bar (recurring) above, are non-terminating & repeating, like, \(0.\bar{2} = 0.2222....\)

Calculation:

Let's assume that,

⇒ k = 0.9999..     … (i)

Multiply by 10 both side, we get

⇒ 10k = 9.999...   … (ii)

Now, we subtract equation (i) from (ii) and get,

⇒ 9k = 9

⇒ k = 1 

∴ The correct answer is p/q = 1/1

Concept used: 

Probability = Number of favorable outcomes / Number of possible outcomes

Calculation:

Number of possible outcomes = 100

Number of favorable outcomes = 12 + 9 + 8 + 8

⇒ 37

Probability = \(37\over100\)

⇒ 0.37

∴ If a number is chosen at random, then the probability that the digit at its unit's place is a non zero multiple of 2, is 0.37

Given:

∠P - ∠Q = 14°

∠Q - ∠R = 29°

Concept used: 

Sum of interior angles of a triangle = 180° 

Calculation:

⇒ ∠P + ∠Q + ∠R = 180° → (1)

⇒ ∠P - ∠Q = 14°

⇒ ∠P = 14° + ∠Q  → (2)

⇒ ∠Q - ∠R = 29°

⇒ ∠R = ∠Q - 29° → (3)

⇒ 14° + ∠Q + ∠Q + ∠Q - 29° = 180° 

⇒ 3∠Q = 180° + 15° 

⇒ 3∠ Q = 195° 

∴  ∠ Q = 65°

Given:

Three numbers a, b and c in order are in A.P and a = 24 and c = 50

Concept used:

In AP, the difference between two consecutive terms is equal.

Calculation:

b - a = c - b

⇒ 2b = a + c

⇒ 2b = 24 + 50

⇒ 2b = 74

∴ 2b = 74

Given:

'x' is the HCF of 117 and 45, And x = 117 y + 45(-5)

Concept used: 

HCF = Highest Common Factor

HCF of two or more numbers is the largest number that can divide each of the numbers without leaving a remainder.

Calculation:

⇒ 117 = 3 x 3 x 13

⇒ 45 = 3 x 3 x 5

⇒ HCF(45, 117) = 3 x 3 = 9

⇒ x = 9

⇒ 9 = 117y + 45(-5)

⇒ 9 = 9(13y + 5(-5))

⇒ 13y - 25 = 1

⇒ 13y = 26

⇒ y = 2

∴ y = 2

O Given:

PQ || RS and PQ = 3RS.

Diagonals PR and QS meet at 'O'

Calculation:

In Δ POQ  and Δ ROS,

⇒ ∠O = ∠ O (Common)

⇒ ∠ORS = ∠OPQ (angles on the same side of transversal)

⇒ ∠OQP = ∠OSR (angles on the same side of transversal)

⇒ Δ POQ  ∼ Δ ROS

⇒ \(\dfrac{ΔPOQ}{ΔROS}\) = \(\dfrac{PQ^2}{RS^2}\)

⇒ \(\dfrac{9RS^2}{RS^2}\)

⇒ 9 : 1

∴ The ratio of the areas of Δ POQ and Δ ROS, is 9 : 1

Given:

The mean of 35 observations is 38.

If one observation is included the mean still remains 38 .

Concept used: 

Average = Sum of observation / Number of observations

Calculation:

Let, the sum of 35 observation = m

⇒  \(m\over35\) = 38

⇒  m = 35 x 38

⇒  m = 1330

Let, the new number added = n

⇒  \(\dfrac{m + n}{36}\) = 38

⇒  1330 + n = 36 x 38

⇒  n = 38(36 - 35)

⇒  n = 38

∴ The included observation is 38.

Given:

AB = 6 cm, BC = 8 cm and AC = 10 cm.and lines PQ, PR and QR are parallel to sides AB, BC and AC respectively.

Concept used: 

Since both pairs of opposite sides are parallel, so PARQ is a parallelogram, PR is the diagonal [ diagonal of a parallelogram divide it into two congruent triangles ]

So, ΔPAR ≅ ΔPQR

Similarly all inner triangles of ABC congruent to each other

Calculation:

P, Q, R are the midpoints of AC, BC, AB respectively

PQ = 1/2AB = 3 cm,

PR = 1/2BC = 4 cm,

QR = 1/2AC = 5 cm,

So, the perimeter of the quadrilateral PARQ is

⇒ PA + AR + RQ + QP

⇒ 5 + 3 + 5 + 3

⇒ 16 cm

∴ The correct answer is 16 cm

Given:

10 packets of sugar, each marked 5 kg actually contained the following weights (in kg): 5.001, 5.050, 4.995, 4.990, 5.010, 4.980, 5.100, 4.975, 5.000, 5.025.

Concept used: 

Probability = Number of favorable outcomes / Number of possible outcomes

Calculation:

Number of packet containing more than 5 kg sugar = 5

Number of possible outcomes = 10

⇒ Probability = \(\dfrac{5}{10}\)

⇒ \(\dfrac{1}{2}\)

∴ The probability that the chosen packet contains more than 5 kg of sugar is \(\dfrac{1}{2}\)

Given:

The perimeter of a sector is 25 cm and the length of the arc is 4 more than its radius

Concept used: 

Perimeter of sector = l + 2r

Area = 0.5lr

Calculation:

⇒ l = 4 + r

⇒ 25 = 4 + r + 2r

⇒ 25 = 4 + 3r

⇒ 3r = 21

⇒ r = 7cm

⇒ l = 11 cm

⇒ Area = 0.5 x 7 x 11

⇒ 38.5 cm²

∴ The area of the sector is 38.5 cm²

Given:

f(x) = x² + x - 2

Concept used: 

αβ = \(c\over a\)

α + β = \(-b\over a\)

Calculation: 

⇒ \(\dfrac{1}{α}+\dfrac{1}{β}+α β\) = \(\dfrac{α + β }{αβ}+α β\)

⇒ αβ = - 2

⇒ α + β = - 1

⇒ \(\dfrac{1}{α}+\dfrac{1}{β}+α β\)

⇒ \(\dfrac{-1}{-2}\) + (- 2)

⇒ \(\dfrac{1-4}{2}\)

⇒ \(-3\over2\)

∴ \(\dfrac{1}{α}+\dfrac{1}{β}+α β = \dfrac{-3}{2}\)

Given:

x - 2y = 3

Concept used: 

A system of equation has infinitely many solutions, if the below is satisfied;

\(\dfrac{A_1}{A_2} = \dfrac{B_1}{B_2} = \dfrac{C_1}{C_2} \)

Calculation:

Option 1:

⇒ \(\dfrac{1}{2} = \dfrac{-2}{-4} \ne \dfrac{3}{9} \)

Option 2:

⇒ \(\dfrac{1}{4} = \dfrac{-2}{-8} = \dfrac{3}{12} \)

∴ 4x - 8y = 12 will form a system of equations with x - 2y = 3 that has infinitely many solutions.

Given: 

 \(8 \frac{2}{7}\)

Calculation:

⇒ 8\(2\over 7\) = \(\dfrac{58}{7}\)

⇒ 8.285714285714...

⇒ 8.\(\overline{285714} \) 

After 6 digits, the digits are repeating.

∴ The maximum number of digits in the repeating block, in the decimal expansion of \(8 \frac{2}{7}\), is 6.

Given:

The supplementary angles are in the ratio 4 ∶ 6

Concept used: 

Supplementary angles are two angles whose sum is equal to 180 degrees.

Calculation:

Let, the two angles be 4m and 6m.

⇒ 4m + 6m = 180°

⇒ 10 m = 180° 

⇒ m = 18° 

⇒ The largest angle = 6 x 18

⇒ 108° 

∴  The larger angle is 108°.

Given:

The distribution of marks obtained by the student is 110, 130, 150 and 170.   

Calculation:

The lower limit of the first class interval is 100.

∴ The correct answer is 100.

Given:

The radii of two circular cylinders are in the ratio 3 ∶ 5 and their lateral surface areas are in the ratio 7 ∶ 10

Concept used: 

Lateral surface area = 2πrh

Calculation: 

⇒ Ratio of Lateral surface area = \(\dfrac{RH}{rh}\)

⇒ \(\dfrac{3H}{5h}\) = \(\dfrac{7}{10}\)

⇒ \(\dfrac{H}{h} \) = \(\dfrac{7}{6}\)

∴ The ratio of their respective heights is 7 : 6.

Given:

A can contains 28 chocolates out of which some are mint chocolates and others are white chocolates.

The probability of selecting a mint chocolate at random is 1/4

Concept used: 

Probability = Number of favorable outcomes / Number of possible outcomes

Calculation:

Let, the number of mint chocolate = m

⇒ 1/4 = m/28

⇒ m = 7

⇒ White chocolates = 28 - 7

⇒ 21

∴ The number of white chocolates is 21.

Shortcut Trick

When a cylinder and a cone share the same internal base radius and height, the volume of the cylinder is exactly 3 times the volume of the cone.

Given Volume of the cone = 2 litres.

Volume of the cylinder = 3 × 2 = 6 litres.

∴ The correct answer is 6 litres.

Alternate Method

Given:

Volume of the hollow cone = 2 litres

Let the internal base radius be r and internal height be h.

Formula Used:

Volume of a Cone = (1/3) × πr²h

Volume of a Cylinder = πr²h

r

h Cylinder: V = ?

r

h Cone: V = 2 L

Calculations:

⇒ Volume of the cone = (1/3) × πr²h = 2

⇒ πr²h = 2 × 3

⇒ πr²h = 6

⇒ Volume of the cylinder = 6 litres

∴ The correct answer is 6 litres.

Additional Information

Volume of a Sphere

The volume of a sphere with radius r is given by the formula V = (4/3) × πr³.

Surface Area of a Cylinder

The curved surface area of a cylinder is 2πrh and the total surface area is 2πr(r + h).

Frustum of a Cone

If a cone is cut by a plane parallel to its base, the remaining lower part is a frustum. Its volume is (1/3) × πh(R² + r² + Rr).

Given:

tan (A - 18) = cot 3A

Concept used: 

tan(90 - θ) = cot θ 

Calculation: 

⇒ cot 3A = tan(90 - 3A)

⇒ tan(90 - 3A) = tan (A - 18)

⇒ 90 - 3A = A - 18

⇒ 4A = 108

⇒ A = 27° 

∴ A = 27°

Given:

A and B are two points having coordinates (1, 4) and (1, -4) respectively and P is any point on AB such that AP = \(\frac{3}{8}\) AB

Concept used: 

P(x, y) = \(\dfrac{mx_2 + nx_1}{m + n} , \dfrac{my_2 + ny_1}{m + n}\)

Calculation:

m = 3

n = 5

⇒ P(x, y) = \(\dfrac{3(1) + 5(1)}{8} , \dfrac{3(-4) +5(4)}{8}\)

⇒ P(x, y) = (1, 1)

∴ The coordinates of P are (1, 1)

Given:

The perimeter, of a sector of a circle of radius 6 cm, is 26 cm. 

Formula used: 

Perimeter = 2r + \(θ\over360 \) × 2πr

Area = πr²×\(θ\over360 \)

Calculation:

⇒ 2r + \(θ\over360 \) × 2πr = Perimeter

⇒ (2 × 6) + \(θ\over360 \) × 2πr = 26

⇒  \(θ\over360 \) × 2πr = 26 - 12

⇒  \(θ\over360 \) × πr = 14/2 = 7    ---------(1)

Area = πr2 × \(θ\over360 \)

⇒ Area = 7 × 6   [ \(θ\over360 \) × πr = 7]

⇒ Area = 42 cm²

∴ The area of the sector is 42 cm²

Given:

\(\frac{x}{y}-\frac{y}{x}=3~ \)

Formula used:

(a - b)² = a² + b² + 2ab

a³ - b³ = (a - b)(a² + b² + ab)

Calculation:

Let, \(x\over y\) = m

⇒ m - \(1\over m\) = 3

Now,

⇒ (m - \(1\over m\))² = 3²

⇒ m² + \(\frac{1}{m^2}\) - 2 = 9

⇒ m2 + \(\frac{1}{m^2}\) = 11

According to the question,

⇒ \(m^3 - \frac{1}{m^3} = (m - \frac{1}{m})(m^2 + \frac{1}{m^2} + 1) \)

⇒ \(m^3 - \frac{1}{m^3} \) = 3 ×  (11 + 1)

⇒ \(m^3 - \frac{1}{m^3} \) = 3 × 12 = 36

⇒ \(\frac{x^3}{y^3}-\frac{y^3}{x^3} \) = 36

∴ The correct answer is 36.

Shortcut TrickIf x - \(\frac{1}{x}\) = a, then \(x^3 - \frac{1}{x^3}\) = a³ + 3a

Now, let x/y = m, we have

m - \(1\over m\) = 3, then \(m^3 - \frac{1}{m^3}\) = 3³ + 3 × 3 = 27 + 9 = 36

Put m = x/y, we get

⇒ \(\frac{x^3}{y^3}-\frac{y^3}{x^3}\) = 36

The correct answer is 'has been practicing.'

Key Points 

• The given sentence tells that the action is taking place since morning and is still in progress, so the sentence will be in Present Perfect Continuous tense.
• We use the Present Perfect Continuous tense to talk about action that started in the past and is continuing now.
• This is often used with for or since.
• "Since" shows an event that began in the past and continues into the present.
• Example: It has been raining since 8 a.m.
• ​Now, let us explore the given options:
• Practices: Simple Present Tense
• Has practiced: Present Perfect tense
• Has been practicing: Present Perfect Continuous tense
• Would practice: Past Tense of "will"
• Therefore, the correct answer is Option 3.

Correct sentence: I'm sorry about this noise you hear. She has been practicing for a concert since morning.

The correct answer is 'expect.'

Key Points   

• The context of the sentence hints that the holiday was perfect if the weather was not bad.
• ​​Except for: We use "except for" to introduce the only thing or person that prevents a statement from being completely true.
• Example: He hadn't eaten a thing except for one forkful of salad.
• Therefore, the correct answer is Option 3.

Correct sentence: Except for the bad weather, our holiday would have been perfect.

Additional Information

• Let us see the usage of other options:
• But: "But" is a coordinating conjunction used to connect ideas that contrast.
• Example: I like him but I can't meet him.
• ​Though: It means ‘in spite of something.’ 
• It is a subordinating conjunction.
• This means that the clause which they introduce is a subordinate clause, which needs a main clause to make it complete.
• When the although clause comes after the main clause, it can also mean ‘but it is also true that …’
• Example: We didn’t make any profit though nobody knows why.
• ​Even: "Even" is an adverb.
• We use "even" to refer to something surprising, unexpected, unusual or extreme.
• Example: He didn't even have enough money to pay the rent.

The correct answer is 'No.'

Key Points   

• Let's understand the meaning and usage of given determiners:
• No: The word 'no' is used with nouns to mean 'no one' or 'not any'.
• It can be used with singular or plural noun.
• Example: No boys were present in the sports class.
• Some: We use "some" before nouns to refer to indefinite quantities.
• We use "some" with plural countable nouns in positive sentences.
• Example: Can you get me some milk?
• Few: "Few" is a quantifier used with plural countable nouns.
• Example: Few members of the family leave their hometown each year.
• • Much: We use "much" if the noun is uncountable (e.g., water, sand).
• When using "much", the noun will always be singular; it cannot be plural.​
• Example: I don't have much money.
• Out of all the options, only "No" can be used for the singular noun "University."
• Hence, the correct answer is 'Option 1.'

Correct sentence: No university is a place for politics.

The correct answer is 'than.'

Key Points 

• "No sooner" is used to show that one thing happens immediately after another thing.
• It is often used with the past perfect, and usually followed by "than."
• Example: They had no sooner arrived than they were arguing.
• ​Therefore, the correct answer is Option 1.

Correct sentence*: No sooner had we started the picnic than the rain began pouring down.*

Additional Information 

• When we begin a sentence with a negative word, we put the auxiliary verb before the subject.
• Example: No sooner had she read the letter than she started crying.

                No sooner she read the letter than she started crying.

The correct answer is 'The government undertakes rural spending at various levels.'

Key Points 

• The given sentence is in Passive Voice and Simple Present tense.
• As per the given question we have to change it into Active Voice.
• The structure of the given sentence is as follows:
• Subject (objective case)+ is/am/were + V3 + Object (subjective case). (Passive Voice)
• Subject + V1(s/es)+ Object. (Active Voice)
• Example:
• Their cousin show them some rare photographs. (Active Voice)
• They are shown some rare photographs by their cousin. (Passive Voice)
• The subject of the given sentence is 'Rural spending' and the object is 'the government'.
• The subject will be put in place of the object and the object will be put in place of the subject.
• The constant object in the given sentence is "at various levels."
• And 'is undertaken' will be changed into 'undertakes'.
• Therefore, the correct answer is 'Option 2.'

Correct sentence: The government undertakes rural spending at various levels.