Question # 1

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

Practically the quantity v/c is always:

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less than one

Equal to one

Greater then one

all of these

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 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

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

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Max. Planck

Maxwell

Bohr

Rutherford

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

When a platinum wire is heated, it appears white at

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1600°C

900°C

1100°C

1300°C

The ratio of energy E to the corresponding frequency (f) of the radiation (emitted or absorbed) is called:

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Wien's constant

Stefen's constnat

Planck's constant

Boltzmann's constant

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 location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

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2 cm/s

20 cm/s

200 cm/s

2000 cm/s

Position was discovered by Carl Anderson in

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1920

1925

1928

1932

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 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

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 stopping voltage for a certain metal is 100 volts, then the work function for the cathode plate is

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100 J

1.6 x 10^-17J

100 eV

1.6 x 10^-17eV

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

Which of the following phenomenon proves the particle nature of light

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interference

diffraction

photoelectric effect

none of these

Compton studied the scattering of x-rays by loosely bound electrons from:

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NaCl crystal

Graphite crystal

Zirconia

Copper crystal

None of these

The speed of a pendulum is measured to be 3.0 s in the inertial reference frame of the pendulum. What is its period measured by an observer moving at a speed of 0.95 c with respect to the pendulum

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2.9 s

3.0 s

6.6 s

9.6 s

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

Compton was awarded Nobel prize in physics in

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1921

1923

1925

1927

The special theory of relativity is based on:

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Four postulates

Three postulates

Two postulates

One postulate

None of these

The inside cavity of the black body is

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painted white

painted silver

blackened with soot

painted red

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)

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 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

Wien's constant is measured in:

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Metre per kelviin

Metre kelvin

Kelvin per meter

Joules

Dynes

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

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

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

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