    # MCQ for Class 11 Physics Chapter 15 Waves with answer

MCQ for Class 11 Physics Chapter 15 : MCQs for Class 11 Physics Chapter 15 Waves with Answers PDF Free Download prepared here according to the latest CBSE RBSE and Other State Board syllabus and NCERT Books.

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## MCQ for Class 11 Physics Chapter 15 Chapter 15 Waves with answer

Q1. A resonance air column of length 40 cm resonates with a tuning fork of frequency 450 Hz. Ignoring end correction, the velocity of sound in air will be

(a) 720 m/s
(b) 820 m/s
(c) 920 m/s
(d) 1020 m/s

(a) 720 m/s

Q2. An observer is moving towards a stationary source of frequency 250 Hz with a velocity of 40 m/s. If the velocity of sound is 330 m/s, the apparent frequency heard by the observer will be

(a) 320 Hz
(b) 300 Hz
(c) 280 Hz
(d) 260 Hz

(c) 280 Hz

Q3. With the increase in temperature, the frequency of the sound from an organ pipe

(a) Decreases
(b) Increases
(c) Remain unchanged
(d) Changes erratically

(b) Increases

Q4. Loudness of a note of sound is

(a) Directly proportional to amplitude of the wave
(b) Directly proportional to square of amplitude of wave
(c) Directly proportional to velocity of the wave
(d) Directly proportional to square of velocity of the wave

(b) Directly proportional to square of amplitude of wave

Q5. The frequency of the note produced by plucking a given string increases as

(a) The length of the string increases
(b) The tension in the string increases
(c) The tension in the string decreases
(d) The mass per unit length of the string increases

(b) The tension in the string increases

Q6. A siren placed at a railway platfrom is emitting sound of frequency 5 kHz. A passenger sitting in a moving train A records a frequency of 5.5 kHz while the train approaches the siren. During his return journey in a different train B he records a frequency of 6.0 kHz while approaching the same siren. The ratio of velocity of train B to that of train A is

(a) 242 / 252
(b) 2
(c) 5 / 6
(d) 11 / 6

(b) 2

Q7. Energy is not carried by

(a) Longitudinal progressive waves
(b) Electromagnetic waves
(c) Transverse progressive waves
(d) Stationary wave

(d) Stationary wave

Q8. The extension in a string, obeying Hookes law is X. The speed of sound in the stretched string is V. If the extension in the string is increased to 1.5 X, the speed of sound will be

(a) 1.22 V
(b) 0.61 V
(c) 1.50 V
(d) 0.75 V

(a) 1.22 V

Q9. Energy is to be carried from one place to another. Which one of the following cannot be used?

(a) Longitudinal progressive waves
(b) Transverse progressive waves
(c) Electromagnetic waves
(d) Standing (stationary) waves

(d) Standing (stationary) waves

Q10. To demonstrate the phenomenon of beats we need

(a) Two sources which emit radiation of nearly the same frequency
(b) Two sources which emit radiation of exactly the same frequency
(c) Two sources which emit radiation of exactly the same frequency and have a definite phase relationship
(d) Two sources which emit radiation of exactly the same wavelength

(a) Two sources which emit radiation of nearly the same frequency

Q11. Four wires of identical lengths, diameters and material and stretched on a sonometer box. The ratio of their tension is 1 : 4 : 9 : 16. the ratio of their fundamental frequencies is

(a) 1 : 6 : 9 : 16
(b) 4 : 3 : 2 : 1
(c) 1 : 2 : 3 : 4
(d) 1 : 4 : 9 : 16

(c) 1 : 2 : 3 : 4

Q12. When a sound wave goes from one medium to another, the quantity that remains unchanged is

a) frequency
b) wavelength
c) amplitude
d) speed

a) frequency

Q13. For which of the following do the longitudinal waves exist?

a) Both
b) Air
c) Water
d) None of these

a) Both

Q14. Sound travels in rocks in the form of

a) both longitudinal and transverse elastic waves
b) non-elastic waves
c) transverse elastic waves only
d) longitudinal elastic waves only

a) both longitudinal and transverse elastic waves

Q15. From a point source, if amplitude of waves at a distance r is A, its amplitude at a distance 2r will be

a) A/2
b) A/4
c) 2 A
d) A

a) A/2

Q16 The property of a medium necessary for wave propagation is

a) All of the above
b) Elasticity
c) Inertia
d) Low resistance

a) All of the above

Q17. The ratio of the speed of a body to the speed of sound is called

a) Mach number
b) Sonic index
c) Doppler ratio
d) Refractive index

a) Mach number

Q18. Sound waves transfer

a) both energy and momentum
b) only energy not momentum
c) momentum
d) energy

a) both energy and momentum

Q19. The reason for introducing Laplace correction in the expression for the velocity of sound in a gaseous medium is

a) no change in the heat of the medium during the propagation of the sound through it
b) no change in the temperature of the medium during the propagation of the sound through it
c) change in the pressure of the gas due to the compression and rarefaction
d) change in the volume of the gas

a) no change in the heat of the medium during the propagation of the sound through it

Q20. Which of the following changes at an antinode in a stationary wave?

a) Neither pressure nor density
b) Both pressure and density
c) Pressure only
d) Density only

a) Neither pressure nor density

Q21. What is the effect of humidity on sound waves when humidity increases?

a) Speed of sound waves is more
b) Speed of sound waves is less
c) Speed of sound waves remains same
d) Speed of sound waves becomes zero

a) Speed of sound waves is more

Q22. Which of the following statements is/are correct about the standing wave?
I. In a standing wave the disturbance produce is confined to the region where it is produced.
II. In a standing wave, all the particles cross their mean position together.
III. In a standing wave, energy is transmitted from one region of space to other

a) I and II
b) Only II
c) Only III
d) I, II and III

a) I and II

## MCQ Questions for Class 11 Physics Multiple Choice Questions with Answers

CBSE RBSE Gujarat Board UP Board Bihar Board MP Board Hariyana Board Panjab Board NCERT Objective MCQ Questions of Class 11 Physics with Answers PDF.