MCQ Questions for Class 11 Physics Chapter 15 Waves with Answers

Here you will find NCERT MCQ Questions for Class 11 Physics with Answers PDF Free Download based on the important concepts and topics given in the textbook as per CBSE new exam pattern. This may assist you to understand and check your knowledge about the chapters. Students also can take a free test of the Multiple Choice Questions of Class 11 Physics. Each question has four options followed by the right answer. These MCQ Questions are selected supported by the newest exam pattern as announced by CBSE.

Q1. When a compression is incident on rigid wall it is reflected as

(a) Compression with a phase change of p
(b) Compression with no phase change
(c) Rarefaction with a phase change of p
(d) Rarefaction with no phase change

(a) Compression with a phase change of p

Q2. 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

Q3. Transverse are generated in two uniform wires A and B by attaching their free ends to a vibrating source of frequency 600 Hz. The diameter of wire A is one-third that of wire B and tension in the wire A is double that in wire B. What is the ratio of velocities of waves of waves in wire A and B?

(a) √3 : 2
(b) 2 : √3
(c) 3 : √2
(d) √2 : 3

(d) √2 : 3

Q4. 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

Q5. String is in fundamental mode of vibration then velocity is directly proportional to _

(a) Square root of tension
(b) Square root of length
(c) Square of tension
(d) Square root of linear density

(a) Square root of tension

Q6. 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

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

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

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. The rate of transfer of energy in a wave depends

a) directly on the square of the wave amplitude and square of the wave frequency
b) directly on the square of the wave amplitude and root of the wave frequency
c) directly on the wave amplitude and square of the wave frequency
d) None of these

a) directly on the square of the wave amplitude and square of the wave frequency

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