191.

Assertion:  Sound waves cannot travel in vacuum but light can travel in vacuum. 

Reason: Sound waves are longitudinal waves and they cannot be polarised but  electromagnetic waves are transverse and they can be polarised.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

A stone thrown into still water, creates a circular wave pattern moving radially outwards. Ifr is the distance measured from the centre of the pattern, the amplitude of the wave varies as

• r^1/2

• r^-1

• r²

• r^3/2

Which of the following diagrams represents the variation of electric field vector with time for a circularly polarized light?

When a guitar string is sounded with a 440 Hz tuning fork, a beat frequency of 5 Hz is heard. If the experiment is repeated with a tuning fork of 437 Hz, the beat frequency is 8 Hz. The string frequency (Hz) is

• 445

• 435

• 429

• 448

For a wave propagating in a medium, identify the property that is independent of the others.

• Velocity

• Wavelength

• Frequency

• All these depend on each other

The waves produced by a motorboat sailing in water are

• transverse

• longitudinal

• longitudinal and transverse

• stationary

Two springs are connected to a block mass M placed on a frictionless surface as shown in figure. If both the springs have a spring constant k, the frequency of oscillation of the block is

An organ pipe closed at one end has a fundamental frequency of 1500 Hz. The maximum number of overtones generated by this pipe which a normal can hear is

• 14

• 13

• 6

• 9

The Magnetic Resonance Imaging (MRI) is based on the phenomenon of

• nuclear magnetic resonance

• electron spin resonance

• electron paramagnetic resonance

• diamagnetism of human tissues

Two springs of force constants k and 2k are connected to a mass as shown in figure . The frequency of oscillation of the mass is

• $\frac{1}{2\mathrm{\pi }}\sqrt{\frac{\mathrm{k}}{\mathrm{m}}}$

• $\frac{1}{2\mathrm{\pi }}\sqrt{\frac{2\mathrm{k}}{\mathrm{m}}}$

• $\frac{1}{2\mathrm{\pi }}\sqrt{\frac{3\mathrm{k}}{\mathrm{m}}}$

• $\frac{1}{2\mathrm{\pi }}\sqrt{\frac{\mathrm{m}}{\mathrm{k}}}$