1.

Two wires of same material and radii r and 2r respectively are welded together end to end. The combination is used as a sonometer wire and kept under tension T. the welded point is mid-way between the two bridges. When stationary waves are set up in the composite wire, the joint is a node. Then the ratio of the number of loops formed in the thinner to thicker wire is, (P.M.T. 90)

(a) 2 : 3

(b) 1 : 2

(c) 2 : 1

(d) 5 : 4

Answer: (b)

2.

A weight of 5 kg is required to produce the fundamental frequency of a sonometer wire. What weight is required to produce its octave?

(a) 10 kg wt

(b) 20 kg wt

(c) 30 kg wt

(d) 40 kg wt

Answer: (b)

3.

The lengths of two organ pipes open at both ends are L and L + d. if they are sounded together, then the beat frequency will be

(a)

(b)

(c)

(d)

Answer: (d)

4.

The speed of sound in air is 350 m/s. the fundamental frequency of the open pipe of length 50 cm is

(a) 100 Hz

(b) 250 Hz

(c) 350 Hz

(d) 400 Hz

Answer: (c)

5.

What is the velocity of transverse waves traveling along a thin copper wire of length 50 cm and mass 1 gram, if it is stretched by a weight of 4 kg?

(a) 60 m/s

(b) 90 m/s

(c) 110 m/s

(d) 140 m/s

Answer: (d)

6.

For a closed organ pipe resonance is occurred when air columns of lengths are equal to (MHT CET 2005)

(a)

(b)

(c)

(d)

Answer: (d)

7.

The radius, density and tension of a string A are twice the radius, density and tension of another string B. if the lengths of the string are equal, the ratio of their frequencies of their vibration (i.e. n_A/n_B) (PMT MP 90)

(a) 1

(b) 2

(c)

(d)

Answer: (c)

8.

A tuning fork of frequency 480 Hz is in unison with pipe closed at one end vibrating in its first overtone. Then fundamental frequency of the pipe is (MHT CET 2006) 

(a) 150 Hz

(b) 160 Hz

(c) 480 Hz

(d) 190 Hz

Answer: (c)

9.

A stretched sting of length l fixed at both ends can sustain stationary wave of wavelength l is given by (MNR 87)

(a)

(b)

(c)

(d) l = 2 l n

Answer: (c)

10.

A pipe closed at one end vibrating in 5^th overtone is in unison with open pipe vibrating in its 5^th overtone. The ratio of l_c : l_o is.  (MHT CET 2006)

(a) 12 : 11

(b) 1 : 1

(c) 11 : 12

(d) 5 : 1

Answer: (c)

11.

Energy is not carried by (M.N.R-86)

(a) Longitudinal progressive waves                     

(b) Electromagnetic waves

(c) Transverse progressive waves                       

(d) Stationary wave

Answer: (d)

12.

With the increase in temperature, the frequency of the sound from an organ pipe (AFMC 76)

(a) Decreases               

(b) Increases

(c) Remain unchanged             

(d) Changes erratically

Answer: (b)

13.

A wire under tension vibrates with a frequency of 450 cycles per sound. What would be the fundamental frequency if the wire were half as long, twice as thick and under one fourth tension (CPMT A.P. 80)

(a) 225 cps

(b) 190 cps

(c) 247 cps

(d) 174 cps

Answer: (a)

14.

In stationary wave the distance between two successive nodes or two successive antinodes is equal to (N.C.E.R.T-76)

(a) l

(b)

(c)

(d)

Answer: (b)

15.

A tube closed at one end and containing air, produces, when excited, the fundamental note of frequency 512 Hz. If the tube is open at both ends, the fundamental frequency that can be excited is (in Hz) (I.I.T. 86)

(a) 1024

(b) 512

(c) 256

(d) 128

Answer: (a)

16.

An open organ pipe has a fundamental frequency of 300 Hz. The first overtone of this organ pipe is the same as the first overtone of a closed organ pipe. The length of the closed organ pipe is (N.C.E.R.T-82)

(a) 10 cm

(b) 41 cm

(c) 82 cm

(d) 164 cm

Answer: (b)

17.

The frequency of the note produced by plucking a given string increases as (NCERT 80)

(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

Answer: (b)

18.

In Meld’s experiment, the string vibrates in 4 loops when a 50 gram weight is placed in the pan of weight 15 gram. The make the string to vibrate is 6 loops the weight that has to be removed from the pan is

(MHT CET 2004)

(a) 0.007 kg wt

(b) 0.0021 kg wt

(c) 0.0036 kg wt

(d) 0.0029 kg wt

Answer: (c)

19.

Velocity of sound in air is 320 m/s. a pipe closed at one end has length of 1 m. neglecting end corrections, the air column in the pipe can resonates for sound of frequency (I.I.T 89)

(a) 80 Hz

(b) 320 Hz

(c) 400 Hz

(d) All (a), (b) & (c)

Answer: (d)

20.

An organ pipe open at both ends and another organ pipe closed at one end will resonate with each other, if their lengths are in the ratio of (EAMCET 92) 

(a) 1: 1

(b) 1: 4

(c) 2: 1

(d) 1: 2

Answer: (c)

21.

The frequency of the second overtone of a closed pipe

is in unison with the third overtone of an open pipe

other ratio of lengths of the pipe is (MHT CET 2001)

(a) 10: 8

(b) 5: 8

(c) 7: 4

(d) 4: 7

Answer: (b)

22.

A vibrating sonometer wire is in resonance with a tuning fork of frequency 150 Hz. If only one loop is formed on the wire and the length of one loop is 40 cm, then the velocity of transverse waves on the wire will be

(a) 120 m/s

(b) 240 m/s

(c) 90 m/s

(d) 60 m/s

Answer: (a)

23.

If n₁ is the resonance frequency of a pipe open at both ends and n₂ the resonance frequency of pipe open at one ends only, and both are vibrating in the fundamental mode and the pipes are of the same length, then (CPMT 86)

(a) n₁ = 2n₂

(b) n₁ = n₂

(c) 2n₁ = n₂

(d) 3n₂ = 4n₂

Answer: (a)

24.

If the end correction of an open organ pipe is 0.8 cm, then the inner radius of the pipe will be

(a)

(b)

(c)

(d)

Answer: (c)

25.

A resonating column of air contains (CPMT 74)

(a) Stationary longitudinal waves                        

(b) Stationary transverse waves

(c) Transverse progressive waves                       

(d) Longitudinal progressive waves

Answer: (a)