JEE Physics — MCQ Practice Questions & Answers

Question 1

A wave travels with a velocity of 300 m/s and has a frequency of 150 Hz. What is its wavelength?

Accepted Answer

Correct answer: A. 2 m — Using v = fλ, where v = 300 m/s and f = 150 Hz, λ = v/f = 300/150 = 2 m

Answer

B. 4 m

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C. 0.5 m

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D. 6 m

Question 2

Which of the following is a characteristic of transverse waves?

Accepted Answer

Correct answer: B. Particles vibrate perpendicular to the direction of wave propagation — In transverse waves, particle oscillation is perpendicular to the direction of wave propagation, such as in electromagnetic waves and ripples on water

Answer

A. Particles vibrate parallel to the direction of wave propagation

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C. No energy is transferred

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D. They can only travel through solids

Question 3

Two waves of the same frequency interfere constructively. The resultant amplitude is:

Accepted Answer

Correct answer: B. The sum of individual amplitudes — In constructive interference, phase difference is 0° or 2πn. Resultant amplitude = A₁ + A₂

Answer

A. The difference of individual amplitudes

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C. Zero

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D. Equal to one of the amplitudes

Question 4

A string of length L is fixed at both ends. The fundamental frequency is f₁. What is the frequency of the second harmonic?

Accepted Answer

Correct answer: B. 2f₁ — For a string fixed at both ends, fₙ = nf₁ where n is the harmonic number. Second harmonic (n=2) has f₂ = 2f₁

Answer

A. f₁

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C. 3f₁

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D. f₁/2

Question 5

Standing waves are formed when:

Accepted Answer

Correct answer: B. Two waves of the same frequency travel in opposite directions — Standing waves result from the superposition of two coherent waves traveling in opposite directions with the same frequency

Answer

A. Two waves of different frequencies travel in the same direction

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C. A single wave is reflected

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D. Waves refract through a medium

Question 6

The velocity of a transverse wave on a string depends on:

Accepted Answer

Correct answer: B. Only tension and mass per unit length — Wave velocity v = √(T/μ), where T is tension and μ is mass per unit length. It is independent of frequency and amplitude

Answer

A. Only frequency

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C. Only amplitude

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D. Frequency and wavelength only

Question 7

When a longitudinal wave travels through a medium, particles undergo:

Accepted Answer

Correct answer: B. Longitudinal oscillation only — In longitudinal waves, particles oscillate parallel to the direction of wave propagation, creating compressions and rarefactions

Answer

A. Transverse oscillation only

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C. Circular motion

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D. Random motion

Question 8

A wave travels on a string with velocity v = 20 m/s. If the frequency is 50 Hz, what is the wavelength?

Accepted Answer

Correct answer: A. 0.4 m — Using v = fλ, we get λ = v/f = 20/50 = 0.4 m

Answer

B. 0.5 m

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C. 1.0 m

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D. 2.0 m

JEE Physics - MCQ Practice Questions