Question # 1

A bar 1.0 m in length and located along x-axix moves with a speed of 0.75 c with respect to a stationary observer. The length of the bar as measured by the stationary observer is

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1.66 m

1.0 m

0.66 m

2.66 m

With the help of 50 K v electron microscope, a resolution of

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0.5 to 1 m to possible

1 m to 10 m is possible

0.5 to 1 nm is possible

1 to 10 nm is possible

The concept of direction is purely:

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Absolute

Relative

Relative to stars always

Relative to the sun always

None of these

The intensity of emitted energy (with wavelength) radiated from a black body at different temperatures was initially measured by:

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Lummer

Planck

Pringsheim

Both (A ) and (B)

Both (A) and (C)

The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes

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2 mo

1.67 mo

0.67 mo

2.67 mo

When the atomic particle are moving with velocities approaching that of light:

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Newton's laws become valid

Relativistic effects become prominent

Botha(A) and (B) are valid

Neither (A)nor (B)

There mass becomes zero.

The nature of radiations emitted by a hot body depends upon its:

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Metarial

Temperature

colour

Volume

Length

If a body reaches a speed equal to the speed of light, then its mass will became

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zero

very small

infinity

none of these

As the light shines on the metal surface, the electrons are ejected

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slowly

instantaneously

either of these

none of these

According to the Max plank, energy is redialed or absorbed in

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discrete packets

continuous waves

either of them

none of these

The value of threshold frequency for different metals is

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different

same

may be different or may be same

none of these

Photoelectrons are emitted when ultraviolet light falls on:

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Casium

Silver

Potassium

Any of these

None of these

When platinum wire is heated, it appears cherry red at

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1600°C

900°C

1100°C

1300°C

The way through which electromagnetic radiations or photons interact with matter depends upon their:

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Wavelength

Frequency

Energy

Temperature

All of these

The special theory of relativity treats problems invoving

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inertial frame of references

accelerating frame of references

both of these

none of these

Electromagnetic radiation or photons interact with matter in

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two distinct ways

three distinct ways

four distinct ways

five distinct ways

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