Question # 1

When platinum wire is heated, it appears cherry red at

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1600°C

900°C

1100°C

1300°C

The energy of a photon is represented by

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h/c²

h/T

hc²

hf/c²

The general theory of relativity treats problems involving

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inertial frame of references

accelerating frame of references

both of these

none of these

The mass of an object will be doubled at speed

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1.6 x 10⁸ms^-1

2.6 X 10⁸ms^-1

2.6 x 10⁷ms^-1

2.6 x 10⁹ms^-1

Davision and Germer performed experiment to verify

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de-Brogile hypothesis

theory of relativity

Newton's law of gravitation

Mass-energy relation

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

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

In photoelectric effect the energy of ejected electrons depend on

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The frequency

The intensity

Both frequency and intensity

None of these

Due to relative motion of observer and the frame of reference of events, time always:

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Dilates itself

Contracts itself

Stretches itself

Both (A) and (C)

None of these

Newton's law of motion do not hold in

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an accelerated frame of reference

an unaccelerated frame of reference

both of these

none of these

Electromagnetic -radiation means:

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Photons

protons

Electrons

Mesons

None of these

Current, voltage, resistance measuring circuit is connected with the galvanometer with the help of switch, known as

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ON switch

off switch

function switch

none of these

When a high energy photon interact with a metal, which of the following effect is most likely to be taken place

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pair production

photoelectric effect

Compton effect

None of these

G.P. Thomson observer experimentally that electrons and neutrons possess

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particle-like properties

wave-like properties

neither particle nor wave like properties

none of these

In order to produce pair production, a photon must have a energy

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0.511 Me v

0.256 Me v

1.02 Me v

0.956 Me v

When a position comes close to an electron they annihilate into photons such that

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each photon has energy 0.51 Me v

each photon has energy 1.02 Me v

each photon has energy 0.25 Me v

none of these

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