Question # 1

The Einstein's changes in length, mass and time are not observed in common life because

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We dont observer then seriously

The masses are too large

Their speed is too small than the speed of right

All of the above

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

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

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

If you are moving at relativistic speed between two points that are a fixed distance apart, then the distance between the two points appers

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larger

shorter

equal

none of these

Photoelectric effect takes place with a photon of:

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Very high energy

Very low energy

Low energy

High energy

None of these

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

S.I. unit of planks constant is

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J-s^-1

J.s

J.s^-2

J.s²

The photoelectric effect, the maximum energy of photoelectrons depends on the

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particular metal surface

frequency of incident light

both of them

none of them

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

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

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)

Photocell is a device which converts

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chemical energy into electrical energy

electrical energy into light energy

heat energy into electrical energy

light energy into electrical energy

An inertial frame is that frame in which

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a>0

a=0

a<0

none of these

According to Einstein, with the great increase in the speed of the body the relativistic length of the body

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Remains constant

Decreases

Increases

Reduces to zero

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)

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

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

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500°C

900°C

1100°C

1300°C

A photon is considered to have

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Momentum

Energy

Wavelength

All of the above

An intertial frame of reference is a frame of reference which is

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at rest

moving with uniform velocity

either at rest or moving with uniform velocity

none of these

Intensity of light determines the:

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Energy of each photon

Number of photons

Speed of photons

Size of photons

None of these

In the compton's effect, it is found that the wavelength of incident x-rays is

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greater than the wavelength of scattered x-rays

equal to the wavelength of scattered x-rays

less than the wavelength of scattered x-rays

any one of these

Electromagnetic -radiation means:

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Photons

protons

Electrons

Mesons

None of these

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

According to Einstein, with the great increase in the speed of the body, the relativistic mass of the body

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Remains constant

Decreases

Increases to infinity

Reduced to zero

When a platinum wire is heated, it appears white at

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1600°C

900°C

1100°C

1300°C

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

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500°C

900°C

1100°C

1300°C

Momentum is a parameter associated with

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wave motion

particle motion

neither wave nor particle motion

none of these

The Nobel Prize on the explanation of photoelectric effect was awarded to:

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Max. Planck

Maxwell

Bohr

Rutherford

None of these

In process of annihilation of matter, the two photons produced move in opposite direction to converse

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momentum

charge

energy

mass

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