Question # 1

According to the special theory of relativity, a moving clock

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runs faster

runs slower

neither runs faster nor slower

all of these

Which of the following phenomenon proves the particle nature of light

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interference

diffraction

photoelectric effect

none of these

Electromagnetic -radiation means:

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Photons

protons

Electrons

Mesons

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

The threshold frequency of sodium is 6 x 10⁶MHz. The cut-off wavelength for this metal will be

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500 m

500 nm

500 km

500 cm

None of these

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

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pair production

photoelectric

Compton effect

None of these

The value of the plank's constant 'h' is given by

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1.6 x 10^-19J

1.67 x 10^-27Kg

6.63 x 10³⁴Js

6.63 x 10^-34Js

Victor de-Brogile received the Nobel prize in physics in

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1925

1929

1932

1935

Which of the following is not an example of intertial frame

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a body placed on the surface of earth

a body placed in a car moving with uniform velocity

a body placed in a car moving with same acceleration

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 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

The special theory of relativity is based on:

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Four postulates

Three postulates

Two postulates

One postulate

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

There is certain frequency below which no electrons are emitted from the metal surface, this frequency is known as

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maximum frequency

minimum frequency

threshold frequency

all of these

When a platinum wire is heated, it appears dull red at about

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500°C

900°C

1100°C

1300°C

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

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)

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

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2.120°A

0.212°A

21.2°A

0.14°

a

The emission of electrons from a metal surface when exposed to light of suitable frequency is called the

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pair production

Compton effect

photoelectric effect

relativity

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

The idea of quantization of energy was proposed by:

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Einstein

Max.Planck

Maxwell

Bohr

Rutherford

According to the electromagnetic wave theory of light, increasing the intensity of incident light should increase the

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number of photoelectrons

size of the photoelectrons

charge on photoelectrons

K.E of photoelectrons

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

When platinum wire is heated, then at the temperature of 500 ^oC, it becomes:

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Yellow

Orange red

Dull red

White

Cherry red

Position was discovered by Carl Anderson in

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1920

1925

1928

1932

The existence of position was predicted by Dirace in

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1920

1925

1930

1928

A black body is

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an ideal absorber

an ideal radiator

both of them

none of them

As compared to the distance measured by an observer on Earth, the distance from Earth to a star measured by an observer in a moving spaceship would seem:

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Smaller

Lerger

Same

Much larger

None of these

The energy of a photon is represented by

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h/c²

h/T

hc²

hf/c²

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

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