Physics Unit 4 Test

A closed organ pipe has fundamental frequency 100 Hz. What frequencies will be produced if its other end is also opened?

• 200, 400, 600, 800,…..

• 100, 300, 500, 700,……

• 200, 300, 400, 500, …..

• 100, 200, 300, 400,…….

Two pipes, one is open, and other is closed at one end, having same length the ratio of their fundamental frequency is

• 1 : 2

• 2 : 1

• 3 : 1

• 4 : 1

When the propagation of longitudinal wave through a material medium takes places, the quantities transmitted in the direction of propagation are

• Energy, momentum and mass

• Energy and mass

• Energy

• Energy and linear momentum

Doppler shift in frequency does not depend upon

• The actual frequency of the wave

• The velocity of the source

• The distance of the source from the listener

• The velocity of the observer

Four wires of identical lengths, diameters and materials are stretched on a sonometer box. The ratio of their tensions is 1 : 4 : 9 : 16. The ratio of their fundamental frequencies is

• 16 : 9 : 4 : 1

• 1 : 2 : 3 : 4

• 4 : 3 : 2 : 1

• 1 : 4 : 9 : 16

An observer is moving towards a stationary source with a speed one fifth of the speed of sound. The frequency of sound heard by the observer will be if v is the speed and f is the original frequency of the sound waves

A metallic wire of 2m length hooked between two points has tension of 10N. If mass per unit length of wire is 0.004 kg/s then fundamental frequency emitted by wire on vibration is:

• 12.5 Hz

• 24 Hz

• 48 Hz

• 6.25 Hz

Any point on a string carrying a wave is moving with its maximum speed when:

• The magnitude of its acceleration is a maximum

• The magnitude of its displacement is a maximum

• The magnitude of its displacement is a minimum

• The magnitude of its displacement is half the amplitude

A source of frequency f sends waves of wavelength λ traveling with speed v in some medium. If the frequency is changed from f to 2f, then the new wavelength and new speed are (respectively):

• 2λ, v

• λ, 2v

• λ/2, v

• λ, v/2

When both source and listener move in the same direction with a velocity equal to half the velocity of sound, the change in frequency of the sound as detected by the listener is:

• 50%

• Zero

• 25%

• None of these