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The correct answer is 50 cm.

Important Points

• Here given compression = 20 and rarefaction = 20.
• So, it makes 20 waves and given length = 10 m = 1000 cm.
• v = f λ
• So, 20 × wavelength = 1000 cm.
• wavelength=1000cm/20
• Wavelength = 50 cm.

Key Points

• A sound is a form of energy that is produced by the vibration of objects.
• Vibrations are rapid to and fro motion of an object.
• Compressions and rarefactions are produced because of the disturbance in the medium caused by sound waves.
• Sound waves propagate because of compressions and rarefactions of the particles of the medium.
• One compression and one rarefaction make one wavelength.
• The length between the compression and rarefaction is called a wavelength.

The correct answer is \(9 \over 8\)

• Here given 4/3 and 3/2 is the absolute refractive index of water and glass respectively.
• The refractive index of glass with respect to water = V(water)/V(glass).
• V(vac.) / V(glass) = 3/2 -- (1)
• V(vac.) / V(water) = 4/3 -- (2)

​By dividing (1) by (2) we will get the ratio V(water)/V(glass)

 \( {{3 \over 2} \over {4 \over 3}} = \frac{3}{2} \times \frac{3}{4} = \frac{9}{8}\) = \(9 \over 8\)

So, the reflective index of glass to water is

The correct option is 9898

Important Points

• The refractive index of a medium is the ratio of the speed of light in a vacuum to the speed of light in the medium.
• It has no units.
• The Refractive index is also equal to the velocity of light c of a given wavelength in empty space divided by its velocity v in a substance, or n = c/v.

Key Points

• The refractive index of water is 1.33.
• Each pair of objects is identified by the refractive index
• The greater value of the reflective index of a medium, the bending of light will be greater.

The correct answer is Green.

• Green wire stands for grounding/ earthing in the electric circuit.
• Earthing is used to protect circuits or devices from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth.
• Green wires are chiefly used for socket purposes. Example AC, geyser, TV, microwave, etc.
• Normally, switches have only 2 wires i.e. neutral and phase.

Important Points

• Red wire signifies the phase (live wire) in an electric circuit.
• Sometimes used in switch legs and interconnection between smoke detectors that are hard-wired into the power system.
• The black wire is used for power in all circuits.
• It carries electricity from the breaker into the source.
• White or Gray wire is neutral wire and takes unused electricity (current) which is sent back to the breakers or the main breaker panel.

The correct answer is charge.

Key Points

• Kirchhoff’s Current Law (KCL) is Kirchhoff’s first law that deals with the conservation of charge entering and leaving a junction.
• Σ I_IN = Σ I_OUT
• To determine the amount or magnitude of the electrical current flowing around an electrical or electronic circuit.
• KCL states that for a parallel path the total current entering a circuit's junction is exactly equal to the total current leaving the same junction.

Important Points

• Kirchhoff’s Voltage Law (KVL) is Kirchhoff’s second law that deals with the conservation of energy around a closed circuit path.
• KVL states that for a closed-loop series path the algebraic sum of all the voltages around any closed loop in a circuit is equal to zero.
• The algebraic sum of all the potential differences around the loop must be equal to zero as ΣV = 0.
• Momentum is a term used in physics to describe the quantity of motion of a moving body, measured as a product of its mass and velocity.
• Newton's 2^nd law of motion related to the momentum that is the rate of change of momentum in an object is directly proportional to the force applied, and the change in momentum will be in the direction of the applied force.
• The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction.
• For example, when wood burns, the mass of the soot, ashes, and gases, equals the original mass of the charcoal and the oxygen when it first reacted.

The correct answer is 13.

• Step by step solution:
• Step 1: Write down the binary number: 1101
• Step 2: Multiply each digit of the binary number by the corresponding power of two: 1x2³ + 1x2² + 0x2¹ + 1x2⁰
• Step 3: Solve the powers: 1x8 + 1x4 + 0x2 + 1x1 = 8 + 4 + 0 + 1
• Step 4: Add up the numbers written above: 8 + 4 + 0 + 1 = 13

So, (1101)₂ = (13)₁₀

Key Points

• (1101)₂ = (?)₈  (Binary to octal conversation)
• Step 1: Write down the binary number (001101)₂, Group all the digits in sets of three starting from the LSB (far right). Add zeros to the left of the last digit if there aren't enough digits to make a set of three. (001 101)
• Step 2: Use the table below to convert each set of three into an octal digit. In this case, 001=1, 101=5.

So, the number 1101 in binary is equivalent to 15 in octal.

• Table for binary to the octal conversation:

The correct answer is Sericulture.

Key Points

• The process of raising silkworms to produce silk is called sericulture or silk farming.
• Sericulture is the production of raw silk by means of raising caterpillars (larvae), those of the domesticated silkworm.
• Silk is a continuous filament within each cocoon.

Additional Information

The correct answer is unicellular and eukaryotic.

• Protista is green, golden, red, and brown unicellular algae large, single eukaryotic cell.
• The nucleus is enclosed by a membrane.
• It is composed of a single cell or a colony of similar cells.
• Protists live in water, in moist terrestrial habitats, and as parasites and other symbionts in the bodies of multicellular eukaryotes.

Important Points

• Whittaker proposed an elaborate five-kingdom classification – Monera, Protista, Fungi, Plantae, and Animalia.
• Carl Woese proposed six-kingdom classification - Animalia, Plantae, Fungi, Protista, Archaea/Archaebacteria, and Bacteria/Eubacteria.
• In the six-kingdom classification, Monera was divided into two parts Archaea and Eubacteria.

Additional Information

The correct answer is Phytochrome.

• Phytochrome is a blue-green plant pigment which regulates plant development, including seed germination, stem growth, leaf expansion, pigment synthesis, and flowering.

Important Points

Key Points

• Phytochrome is responsible for the absorption of red and far-red light and it is involved in red-far red light interconversion.
• Photoperiodism is the effect of duration of light and darkness on the growth, development and behaviour of organisms.
• Compound florigen is synthesized in photoperiodism which is responsible for flowering of plants.

The correct answer is Ligament.

• A Ligament is a fibrous connective tissue, which connects bone to another bone.

Important Points

Key Points

• There are 3 types of bone tissue:
• Compact tissue: The harder, outer tissue of bones.
• Cancellous tissue: The sponge-like tissue inside bones.
• Subchondral tissue: The smooth tissue at the ends of bones, which is covered with another type of tissue called cartilage.

The correct answer is Rhizophora.

• Many mangrove species show some form of vivipary. Rhizophora is an example.
• The ovum is fertilized while still on the parent tree and grows by a combination of photosynthesis and acquisition of nutrients from the parent.

Important Points

• In viviparous germination, the seeds germinate while still attached to the parent plant.
• The growth of the embryo continues until it pierces the seed coat, while still attached to the mother plant, without cessation of activity.

Key Points

• Difference between germination and vivipary: