Search Previous Year Questions

The correct answer is joule.

• The unit of heat in the SI system is Joule.
• A unit of energy equal to the work done when a force of one newton acts through a distance of one meter.

Important Points

• The other common units for heat are-
• BTU (Btu) - British Thermal Unit - also known as a "heat unit" in the United States.
• Calorie: The amount of heat required to raise the temperature of one gram of water 1^oC.
• Erg is a unit of energy.
• It equal to the force of one dyne over a distance of one centimeter.
• 1 erg = 10^-7 joule.
• Watt is a unit (SI) of power.
• It is equal to one joule of work performed per second.
• 1 horsepower = 746 watt

Key Points

• 1 joule = 0.14 calorie = 9.478 x 10^-4 Btu.
• 4.184 joule of heat energy (or one calorie) is required to raise the temperature of a unit weight (1 g) of water from 0^oC to 1oC, or from 32^oF to 33.8^oF.
• 1 dyne = 0.00001 newton.

The correct answer is ​ \(P = \dfrac{\vec{F}}{A}\)

• Pressure is defined as the force divided by the area perpendicular to the force over which the force is applied.
• The SI unit for pressure is the pascal, 1 Pa = 1N/m².

Key Points

• A force has both magnitude and direction, therefore: Force is a vector quantity
• Muscular force is being applied by a vendor when he is pushing the pushcart.
• Opening a door is an example of a Contact force.
• Magnet is an example of a Non-contact force.

Concept:

The correct answer is 3 units.

• Newton's 2^nd law of motion says the rate change of momentum is called force.
• The equation for the change in momentum is F ×  t = m ×  Δv
• If the momentum of a body increases from 10 units to 25 units in 5 seconds.
• Then the change in the momentum is 25 – 10 = 15 units in time 5 seconds.
• So the Force extract from this is 15/5 = 3 Newton.

Key Points

• Momentum is a vector quantity that is the product of the mass (weight) of a particle and its velocity (speed).
• SI unit: kilogram meter per second (kg⋅m/s).
• A spinning object has angular momentum.
• An object travelling with a velocity has linear momentum.
• A change in momentum may result from an acceleration or a force or an impulse.

The correct answer is good conductor of heat but bad conductor of electricity.

• Mica is a group of hydrous potassium, aluminum silicate minerals.
• Micas are found in three major rock varieties—igneous, sedimentary, and metamorphic.
• Mica is silicate minerals, known as sheet silicates because it forms in distinct layers.
• Mica is one of the most important mineral ingredients in cosmetics, used widely to add shimmer and sparkle.

Important Points

• Mica is a good conductor of heat but an electrical insulator.
• Electricity needs charged particles (or quasi-particles) to conduct it.
• Heat can be conducted with almost any quasi-particle.

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Key Points

• Diamond is one of the best conductors of heat.
• Koderma, in Jharkhand, is the leading producer of mica.

The correct answer is 90°.

• The angles of dip at the poles and the equator respectively are 90°, 0°.
• The magnetic poles are defined as the area where the dip is vertical.
• The magnetic equator is where the dip or inclination is zero.
• The Earth acts like a large spherical magnet.
• It is surrounded by a magnetic field that changes with time and location.

Important Points

• At the magnetic poles, a dip needle stands vertical (dip=90 degrees), the horizontal intensity is zero, and a compass does not show direction.
• At the north magnetic pole, the north end of the dip needle is down.
• At the south magnetic pole, the north end is up.
• At the magnetic equator, the dip or inclination is zero.

Key Points

• The axis of the dipole is offset from the axis of the Earth's rotation by approximately 11 degrees.
• The lines of forces due to the earth's horizontal component of the magnetic field are parallel straight lines.

The correct answer is water.

• Photosynthesis uses carbon dioxide and water to assemble carbohydrate molecules (usually glucose) and releases oxygen into the air.
• Carbon dioxide is the byproduct of respiration.
• In this process, water and carbon dioxide react in the presence of sunlight to give off oxygen and form glucose molecules.
• Photolysis of water is the source of oxygen liberated in photosynthesis.
• The process is explained through the following equation:
• 6 CO2 + 6 H2O + light → C6H12O6 + 6 O2

Where, CO2 is Carbon Dioxide

H2O is Water

C6H12O6 is Sugar 

O2 is Oxygen

Important Points

• With the help of chlorophyll, plants obtain their nutrients and water from the soil, and sunlight provides solar energy for photosynthesis.
• The proportion of carbon in their chemical makeup can rise on a particularly sunny day because more photosynthesis occurs.

Key Points

• The fungus receives sugar from the plant—made by photosynthesis in the leaves and transported to the roots via the plant’s sap.
• In places where there is no sunlight, organisms producing their food are called chemotrophs.
• Those in the deep ocean, organisms get the energy from chemicals released by hydrothermal vents.
• Bacteria can do photosynthesis.

The correct answer is heparin.

• Heparin is an anticoagulant (blood thinner) that prevents the formation of blood clots.
• It is also used before surgery to reduce the risk of blood clots.

Important Points

The correct answer is pancreas.

• Islets of Langerhans are islands of endocrine cells scattered throughout the pancreas.
• The islets of Langerhans are a cluster of cells within the pancreas that are responsible for the production and release of hormones that regulate glucose levels.
• These cells discovered by Dr. Paul Langerhans.
• Pancreatic islets house three major cell types:
• Alpha cells (A cells) secrete the hormone glucagon.
• Beta cells (B cells) produce insulin.
• Delta cells (D cells) secrete the hormone somatostatin, which is also produced by a number of other endocrine cells in the body.

Important Points

• The stomach is the widest part of the digestive system. It not only digests food, it also stores it.
• The stomach is a bean-shaped sack located behind the lower ribs.
• The stomach secretes hydrochloric acids and enzymes that break down the food so that it can continue on its journey through the digestive system.
• This process called peristalsis (mix the food with the acid and enzymes).
• The human liver is the largest glandular organ of the human body and the second largest organ besides our skin.
• Some of these important functions include supplying glucose to the brain, combating infections, and storing nutrients.
• the liver detoxifies the harmful things we take in like alcohol and drugs.
• The liver creates the blood that circulates in bodies. The liver starts producing blood before born.
• The liver has the amazing ability to regenerate itself, making liver transplant possible.
• Heart is a part of circulatory system and responsible for pumping oxygen-rich blood throughout our body.
• An electrical system controls the rhythm of your heart. It’s called the cardiac conduction system.
• Cardiac muscle is a special type of muscle tissue that's only found in your heart.
• Coordinated contractions of cardiac muscle, which are controlled by special cells called pacemaker cells, allow for your heart to pump blood as a single functional unit.

Key Points

• The first open-heart surgery occurred in 1893. It was performed by Daniel Hale Williams, who was one of the few black cardiologists in the United States at the time.
• The first implantable pacemaker was used in 1958. Arne Larsson, who received the pacemaker, lived longer than the surgeon who implanted it.

The correct answer is protein.

• Enzymes are proteins.
• They are high molecular weight compounds made up principally of chains of amino acids linked together by peptide bonds.
• Enzymes can be denatured and precipitated with salts, solvents, and other reagents.
• Enzymes function as organic catalysts. A catalyst is a chemical involved in, but not changed by a chemical reaction.
• The enzyme speeds up the reaction by lowering the activation energy needed for the reaction to start.

Important Points

The correct answer is Ascorbic acid.

• Vitamin C, also known as ascorbic acid or L-ascorbic acid.
• The richest sources of ascorbic acid including Indian gooseberry, citrus fruits such as limes, oranges, and lemons, tomatoes, potatoes, papaya, green and red peppers, kiwifruit, strawberries, etc.
• Deficiency of Vitamin C and iron often occur in anemia.

Important Points

• Formic acid is also known as methanoic acid (HCOOH).
• It is naturally found in ants.
• It is made by the action of sulphuric acid upon sodium formate, which is produced from carbon monoxide and sodium hydroxide.
• Maleic acid is a butanediol acid in which the double bond has a cis- (Z)-configuration.
• It found in many fruits, including apricots, blackberries, blueberries, cherries, grapes, mirabelles, peaches, pears, plums, and quince
• Maleic acid is present in the apple.
• Palmitic Acid is a saturated long-chain fatty acid with a 16-carbon backbone.
• It found naturally in palm oil and palm kernel oil, as well as in butter, cheese, milk, and meat.
• The palmitic acid is attached to the alcohol form of vitamin A, called retinol, to make vitamin A stable in milk.