1.

If x = a sinand x’ = a cos wt, then what is the phase difference between the two waves

(RAJ PMT-96)

(a)                 

(b)

(c)                 

(d) p

Answer: (a)

2.

When a sound wave of frequency 300 Hz passes through a medium, the maximum displacement of a particle of the  medium is 0.1 cm. the maximum velocity of the particle is equal to (MNR-92)

(a) 60 p cm/s    

(b) 30 p cm/s

(c) 30 cm/s       

(d) 60 cm/s

Answer: (a)

3.

Two tuning forks A and B vibrating simultaneously produce 5 beats. Frequency of B is 512 Hz. It is seen that if one arm of a is filed, then the number of beats increases. Frequency of A will be (PMTMP-91)

(a) 502 Hz        

(b) 507 Hz

(c) 517 Hz        

(d) 522 Hz

Answer: (c)

4.

A simple harmonic wave having amplitude A and time period T is represented by the equation y = 5 sin

p(t + 4) metres. Then the value of A (in metres) and T (in seconds) are (MNR-91)

(a) A = 5, T = 2

(b) A = 10, T = 1

(c) A = 5, T = 1

(d) A = 10, T = 2

Answer: (a)

5.

Which one of the following cannot represent a traveling wave (NCERT-84)

(a) y = f (x - nt)

(b) y = y_m sin k (x + nt)

(c) y = y_m log (x - nt)

(d) y = f (x² - nt²)

Answer: (c)

6.

Which of the following statements is wrong

(NCERT-76)

(a) Sound travels in a straight line                      

(b) Sound travels as waves

(c) Sound is a from of energy                 

(d) Sound travels faster in vacuum that then in air

Answer: (d)

7.

The equation of a progressive wave traveling on a stretched string is y = 10 sin where x and y are in cm and t is in sec. what is the speed of the wave?

(a) 500 cm/s     

(b) 50 m/s

(c) 40 m/s        

(d) 400 cm/s

Answer: (b)

8.

When a compression is incident on rigid wall it is reflected as (MHT-CET 2006)

(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

Answer: (a)

9.

The wavelength of sound in air is 10 cm. its frequency is, (Given velocity of sound = 330 m/s) (CPMT-74)

(a) 330 cycles per second                      

(b) 3.3 kilo cycles per second

(c) 30 mega-cycles per second               

(d) 3 × 10⁵ cycles per second

Answer: (b)

10.

Two waves are represented by

y₁ = a sin and y₂ = a cos wt. what will be their resultant amplitude? (RAJ PMT-96)

(a) a

(b)

(c)              

(d) 2 a

Answer: (c)

11.

Sound waves having the following frequencies are audible to human beings (CPMT-75)

(a) 5 c/s           

(b) 27000 c/s

(c) 5000 c/s      

(d) 50,000 c/s

Answer: (c)

12.

A sound wave is represented by

y = a sin (1000pt - 3x). the distance between two points having a phase difference of 60° is

(MHT CET 2003)

(a)               

(b)

(c)                 

(d)

Answer: (c)

13.

The equation of wave traveling along string is y = 3 cos p (100t - x) in C.G.S. unit then wavelength is

(CPMT-91, MPPMT-94,97, MNR-85)

(a) 1 m            

(b) 2 cm

(c) 5 cm           

(d) None of above

Answer: (b)

14.

A siren emitting a note of frequency n is fitted on a police van, traveling towards a stationary listener. What is the velocity of the van, if the frequency of he note heard by the listener is double the original frequency?

(a) V_S = V         

(b)

(c) V_S = 2V        

(d)

Answer: (b)

15.

In the longitudinal waves the direction of vibration in medium of particle is (MHT-CET 2005)

(a) Perpendicular to propagation of wave            

(b) Parallel to propagation

(c) Different from each other                  

(d) Variable for time to time.

Answer: (b)

16.

The relation between frequency n, wavelength l and velocity n of a wave is (CPMT 76, 85)

(a) n = nl         

(b) n = nl

(c)            

(d)

Answer: (b)

17.

With the propagation of a longitudinal wave through a material medium the quantities transmitted in the propagation direction are (CBSE-92)

(a) Energy, momentum and mass                       

(b) Energy

(c) Energy and mass      

(d) Energy and linear momentum

Answer: (d)

18.

A wave is represented by the equation

y = A sin (10px + 15pt + ), where x is in meters and t is in seconds. The expression represents (IIT-90)

(a) A wave traveling in the positive x-direction with a velocity 1.5 m/s                    

(b) A wave traveling the negative x-direction with a velocity 1.5 m/s

(c) A wave traveling in the negative x-direction have a wave-length 0.2 m              

(d) Both ‘b’ and ‘c’

Answer: (d)

19.

Loudness of a note of sound is (MHT-CET 99)

(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

Answer: (b)

20.

The velocity of sound is maximum in (AFMC Pune 98)

(a) Water         

(b) Air

(c) Vacuum       

(d) Metal

Answer: (d)

21.

A wave is represented by the equation

y = 7 sin , where x is in meters and t is in seconds. The speed of the wave is,

(a) 175 p m/s    

(b) (49 p) m/s

(c) (49 / p) m/s

(d) (0.28 p) m/s

Answer: (a)

22.

Two wave having the intensities in the ratio of 9: 1 produce interference. The ratio of maximum to minimum intensity is equal to (MNR-87)

(a) 10 : 8         

(b) 9 : 1

(c) 4 : 1           

(d) 2 : 1

Answer: (c)

23.

Two tuning forks of frequencies 256 and 258 vibrations/second are sounded together. Then the time interval between two consecutive maxima heard by an observer is  (PMT - MP-88)

(a) 2 sec          

(b) 0.5 sec

(c) 250 sec       

(d) 252 sec

Answer: (b)

24.

Two waves are y₁ = 0.25 sin 316t,

y₂ = 0.25 sin 310t are traveling in same direction. The number of beats produced per second will be

(CPMT-93)

(a) 6

(b) 3

(c)                 

(d) 3p

Answer: (c)

25.

What is phase difference between two successive troughs in the transverse wave?

(a)                 

(b) p

(c)                

(d) 2p

Answer: (d)