JEE Physics Sound Waves MCQs Set 11

Multiple Choice Questions (MCQs) for JEE Physics: Sound Waves

Review structured MCQ sets for JEE Physics Sound Waves. Built according to official JEE guidelines, these downloadable questions support daily revision and core concept reinforcement.

Practice Sound Waves MCQs for JEE Physics

Access the complete set of multiple-choice questions for Sound Waves below. This focused format allows students to isolate specific topics for thorough review and uninterrupted practice alongside official JEE textbooks.

Multiple Choice Questions

Question 1: Which property makes the difference between progressive and stationary waves?
(a) Amplitude
(b) Frequency
(c) Propagation of energy
(d) Phase of the wave
Show Answer & Explanation

Answer: (c) Propagation of energy

Explanation:
1. A progressive wave transports energy along the medium, while a stationary wave does not transmit net energy.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 2: If the amplitude of waves at a distance r from a point source is A, the amplitude at a distance 2r will be
(a) 2A
(b) A
(c) A/2
(d) A/4
Show Answer & Explanation

Answer: (c) A/2

Explanation:
1. Intensity \( \propto 1/r^2 \) and \( I\propto A^2 \), so \( A\propto1/r \); at 2r the amplitude is \( A/2 \).

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 3: When a tuning fork of frequency 341 Hz is sounded with another tuning fork, six beats per second are heard. When the second fork is loaded with wax and sounded with the first, the number of beats is two per second. The natural frequency of the second fork is
(a) 334 Hz
(b) 339 Hz
(c) 343 Hz
(d) 347 Hz
Show Answer & Explanation

Answer: (d) 347 Hz

Explanation:
1. The second fork has 335 or 347 Hz.
2. Loading lowers its frequency, and the beats fall to 2 only if it was 347 Hz (falling to 343 Hz).

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 4: A source of sound of frequency 90 vibrations per second is approaching a stationary observer with a speed equal to 1/10 the speed of sound. The frequency heard by the observer is
(a) 80 vibrations/s
(b) 90 vibrations/s
(c) 100 vibrations/s
(d) 120 vibrations/s
Show Answer & Explanation

Answer: (c) 100 vibrations/s

Explanation:
1. \( f' = \frac{f}{1-v_s/v} = \frac{90}{0.9} = 100 \) Hz.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 5: The driver of a car travelling at 30 m/s towards a hill sounds a horn of frequency 600 Hz. If the speed of sound is 330 m/s, the frequency of the reflected sound heard by the driver is
(a) 720 Hz
(b) 555.5 Hz
(c) 550 Hz
(d) 500 Hz
Show Answer & Explanation

Answer: (a) 720 Hz

Explanation:
1. \( f' = 600\times\frac{330+30}{330-30} = 600\times1.2 = 720 \) Hz.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 6: A source of sound S is moving with velocity 50 m/s towards a stationary observer. The observer measures the frequency of the source as 1000 Hz. The apparent frequency when the source is moving away from the observer after crossing him is (speed of sound 350 m/s)
(a) 750 Hz
(b) 857 Hz
(c) 1143 Hz
(d) 1333 Hz
Show Answer & Explanation

Answer: (a) 750 Hz

Explanation:
1. True frequency \( f_0 = 1000\times\frac{350-50}{350} = 857.1 \) Hz.
2. Receding: \( f = 857.1\times\frac{350}{400} = 750 \) Hz.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 7: Standing waves can be produced in which of the following cases? (1) on a string clamped at both ends (2) on a string clamped at one end and free at the other (3) when an incident wave is reflected from a wall (4) when two identical waves with a phase difference of \( \pi \) move in the same direction
(a) (1), (2) and (3) only
(b) (2), (3) and (4) only
(c) (1) and (4) only
(d) (1), (2), (3) and (4)
Show Answer & Explanation

Answer: (a) (1), (2) and (3) only

Explanation:
1. Standing waves arise from superposition of waves moving in opposite directions: cases 1, 2 and 3.
2. Waves moving in the same direction give a travelling wave, not a standing wave.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 8: Two waves of equal frequency f and velocity v travel in opposite directions along the same path with amplitudes A and 3A. Which of the following are correct? (1) the amplitude of the resulting wave varies between a maximum of 4A and a minimum of zero (2) the average displacement at any point on the path is zero (3) the positions of maxima and minima of amplitude do not change with time
(a) (1) and (2) only
(b) (2) and (3) only
(c) (1) and (3) only
(d) (1), (2) and (3)
Show Answer & Explanation

Answer: (b) (2) and (3) only

Explanation:
1. The amplitudes vary between \( 3A+A = 4A \) and \( 3A-A = 2A \), not zero, so (1) is false.
2. The displacement at each point oscillates symmetrically, giving zero average, and the pattern of maxima and minima is fixed in space.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 9:
Assertion (A): Speed of wave = wavelength / time period.
Reason (R): Wavelength is the distance between two nearest particles in phase.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. In one time period the wave advances one wavelength, so \( v = \lambda/T \). R gives the meaning of wavelength used in this derivation.

Teacher's Note:
1. Decide whether the assertion is true from the wave relations.
2. Then check whether the reason is true and whether it explains the assertion.

Question 10:
Assertion (A): The velocity of sound increases with increase in humidity.
Reason (R): The velocity of sound does not depend upon the medium.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (c) A is true, but R is false.

Explanation:
1. Humid air is less dense, so sound travels faster. A is true.
2. R is false: the speed depends on the elasticity and density of the medium.

Teacher's Note:
1. Decide whether the assertion is true from the wave relations.
2. Then check whether the reason is true and whether it explains the assertion.

Question 11:
Assertion (A): The speed of sound in solids is maximum though their density is large.
Reason (R): The coefficient of elasticity of a solid is large.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. \( v = \sqrt{E/\rho} \); the very large elastic modulus of solids more than compensates for their larger density, so R explains A.

Teacher's Note:
1. Decide whether the assertion is true from the wave relations.
2. Then check whether the reason is true and whether it explains the assertion.

Question 12:
Assertion (A): Sound travels faster in solids than in gases.
Reason (R): Solids possess greater density than gases.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Explanation:
1. \( v = \sqrt{E/\rho} \): solids are faster because their elasticity is very much larger.
2. R is true but density alone would reduce the speed, so it is not the explanation.

Teacher's Note:
1. Decide whether the assertion is true from the wave relations.
2. Then check whether the reason is true and whether it explains the assertion.

Question 13: Two waves \( y_1 = A\cos(0.5\pi x-100\pi t) \) and \( y_2 = A\cos(0.4\pi x-92\pi t) \) travel in a pipe placed along the x-axis. The number of times the intensity is maximum on superposition in a time interval of 1 s is
(a) 4
(b) 6
(c) 8
(d) 10
Show Answer & Explanation

Answer: (a) 4

Explanation:
1. The frequencies are 50 Hz and 46 Hz, so the beat frequency is 4 Hz.
2. The intensity is maximum 4 times per second.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 14: Two sources A and B have frequencies \( \nu_A \) (known) and \( \nu_B \) (unknown) and produce n beats per second. On slightly loading A, the number of beats increases. Then the frequency of B is
(a) \( \nu_B = \nu_A \)
(b) \( \nu_B = \nu_A-n \)
(c) \( \nu_B = \nu_A+n \)
(d) \( \nu_B = \nu_A\pm n \)
Show Answer & Explanation

Answer: (c) \( \nu_B = \nu_A+n \)

Explanation:
1. Loading lowers \( \nu_A \). The beats increase only if \( \nu_A \) moves further from \( \nu_B \), i.e. \( \nu_B>\nu_A \).
2. Hence \( \nu_B = \nu_A+n \).

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 15: Match the types of waves with their frequency ranges. (A) infrasonic (B) audible (C) ultrasonic (D) supersonic. (1) objects moving faster than sound in air at \( 0^\circ \)C (2) frequency below 20 Hz (3) frequency above 20,000 Hz (4) frequency between 20 Hz and 20,000 Hz
(a) A-4, B-3, C-2, D-1
(b) A-2, B-4, C-3, D-1
(c) A-4, B-4, C-1, D-2
(d) A-3, B-2, C-1, D-4
Show Answer & Explanation

Answer: (b) A-2, B-4, C-3, D-1

Explanation:
1. Infrasonic: below 20 Hz; audible: 20 Hz to 20 kHz; ultrasonic: above 20 kHz; supersonic refers to speeds greater than the speed of sound.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 16: Match the description with the term. (A) source speed greater than wave speed produces a conical high-pressure wavefront (B) the loud bang heard when this reaches an observer (C) wave produced by a motorboat exceeding the speed of surface water waves (D) wave produced by charged particles moving faster than light in a medium. (1) shock wave (2) sonic boom (3) bow wave (4) Cerenkov radiation
(a) A-1, B-2, C-3, D-4
(b) A-4, B-3, C-2, D-1
(c) A-3, B-2, C-1, D-4
(d) A-2, B-1, C-4, D-3
Show Answer & Explanation

Answer: (a) A-1, B-2, C-3, D-4

Explanation:
1. A conical high-pressure wavefront is a shock wave; the bang is a sonic boom; a motorboat makes a bow wave; particles faster than light in a medium emit Cerenkov radiation.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 17: A light pointer fixed to one prong of a tuning fork touches gently a smoked vertical plate. The fork is set vibrating and the plate is allowed to fall freely. Two complete oscillations are traced when the plate falls through 40 cm. The frequency of the tuning fork is about (\( g = 9.8 \) m/s\(^2\))
(a) 3.5 Hz
(b) 7 Hz
(c) 14 Hz
(d) 28 Hz
Show Answer & Explanation

Answer: (b) 7 Hz

Explanation:
1. Fall time \( t = \sqrt{\frac{2\times0.4}{9.8}} = 0.286 \) s.
2. \( f = \frac{2}{0.286} \approx 7 \) Hz.

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Question 18: A source of sound S of frequency 500 Hz situated between a stationary observer O and a wall W moves towards the wall with a speed of 2 m/s. If the velocity of sound is 332 m/s, the number of beats per second heard by the observer is approximately
(a) 2
(b) 4
(c) 6
(d) 12
Show Answer & Explanation

Answer: (c) 6

Explanation:
1. Direct sound (source receding from observer): \( f_1 = 500\times\frac{332}{334} = 497 \) Hz.
2. Reflected sound (source approaching the wall): \( f_2 = 500\times\frac{332}{330} = 503 \) Hz.
3. Beats \( = f_2-f_1 \approx 6 \).

Teacher's Note:
1. Identify the wave parameters from the equation or the given data before substituting.
2. Check that the units of v, f and \( \lambda \) are consistent.

Free study material for Physics

Multiple Choice Questions (MCQs) for JEE Physics Sound Waves

Download Multiple Choice Questions: Sound Waves (JEE Physics)

Explore reliable practice questions for Sound Waves tailored for JEE Physics learners. Use these multiple-choice formats to evaluate preparedness and strengthen problem-solving skills.

Concept Clarification for Sound Waves

Cross-reference your completed choices with comprehensive NCERT solutions for JEE Physics to ensure absolute clarity across all sub-topics in this chapter.

Additional Study Resources for JEE Physics

Wrap up your chapter revision by testing your knowledge against standard question formats. Everything on our platform is provided free of charge.

FAQs

Where can I access latest JEE Physics Sound Waves MCQs Set 11?

You can get most exhaustive JEE Physics Sound Waves MCQs Set 11 for free on StudiesToday.com. These MCQs for JEE Physics are updated for the 2026-27 academic session as per JEE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Physics JEE material?

Yes, our JEE Physics Sound Waves MCQs Set 11 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the JEE paper is now competency-based.

How do practicing Physics MCQs help in scoring full marks in JEE exams?

By solving our JEE Physics Sound Waves MCQs Set 11, JEE students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Physics.

Do you provide answers and explanations for JEE Physics Sound Waves MCQs Set 11?

Yes, Physics MCQs for JEE have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused JEE exams.

Can I practice these Physics JEE MCQs online?

Yes, you can also access online interactive tests for JEE Physics Sound Waves MCQs Set 11 on StudiesToday.com as they provide instant answers and score to help you track your progress in Physics.