Question # 1

the symbol to be used in relativity problems denotes:

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Dilated time

Proper time

Life time

Half time

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

When monochromatic light is allowed to fall on cathode, it begins to emit electrons, these electrons are called

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thermoionic electrons

free electrons

photoelectrons

slow electrons

An inertial frame is that frame in which

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a>0

a=0

a<0

none of these

Absolute motion cannot be detected

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in its own frame of references

in a different frame of references

both in its frame and different frame of references

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

There is no way to detect:

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Absolute uniform motion

Accelerated motion

State rest

State of motion

None of these

The special theory of relativity is based on the

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one postulate

two postulates

three postulates

four postulates

Strictly speaking, the earth is:

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An accelerated frame of reference

A non-inertial frame of reference

An inertial frame of reference

^{A non-accelerated frame of reference}

Both (A) and (B)

The whole shape of the black body spectrum for all wavelengths was explained by the formula proposed by

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Max plank

Newton

Einstein

J.J. Thomson

Photoelectrons are emitted when ultraviolet light falls on:

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Casium

Silver

Potassium

Any of these

None of these

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

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classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

The energy of a photon in a beam of infrared radiation of wavelength 1240 nm is

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100 ev

10⁶e v

10³e v

1.0 e v

Compton was awarded Nobel prize in physics in

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1921

1923

1925

1927

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

A high temperature, the proportion of shorter wavelengths radiation, emitted by the body

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decreases

first increases then decreases

increases

any one of them

Momentum is a parameter associated with

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wave motion

particle motion

neither wave nor particle motion

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

The length contraction happens only

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Opposite to the direction of motion

along the direction of motion

perpendicular to the direction of motion

In any direction

The Stephen-Boltzmann law for the black body radiation is given by

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E = T²

E = -T²

E = T⁴

E = -T⁴

Electromagnetic -radiation means:

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Photons

protons

Electrons

Mesons

None of these

A particle having mass and charge equal to that of an electron is called:

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Proton

Positron

Pion

Pi-meson

Both (C) and (D)

When a platinum wire is heated, it appears orange red at

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500°C

900°C

1100°C

1300°C

The energy of the 4th orbit in hydrogen atom is

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2.5 ev

- 3.5 ev

-0.85 ev

-13.6 ev

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

0.1 kg mass will be equivalent to the energy

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9 x 10¹⁵J

5 x 10⁸J

6 x 10¹⁶J

9 x 10^-16J

Pair production is the phenomenon in which

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matter is converted into energy

energy is converted into matter

light is converted into electrical energy

electrical energy is converted into light

If A represents linear momentum and c, the velocity of light, then unit of pc in international system of units is:

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Newton

Joule

Joule-Sec

Joule-s^-1

Watt

Victor de-Brogile received the Nobel prize in physics in

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1925

1929

1932

1935

According to the special theory of relativity

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mass and energy are same entities

mass and energy are same entities but interconverible

mass and energy are different entities but interconverible

mass and energy are different entities but non-interconveritble

The value of the Stephen's constant for black body radiations is given by

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5.6 x 10⁸Wm^-2K^-4

5.67 x 10^-8Wm^-2K^-4

2.9 x 10^-3mK

2.9 x 10³mK

Compton shift refers to:

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Photon

Meson

Proton

Positron

Both (B) and (D)

When a position comes close to an electron they annihilate into

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one photon

two photons which travel in the same direction

two photons which travels in the opposite direction

two photons which travel in any direction

At the temperature, a body emits radiation which is principally

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of long wavelengths in the visible region

of long wavelengths in the invisible infrared region

of short wavelength in invisible ultraviolet region

none of these

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