Question # 1

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

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

From the theory of relativity, momentum p of the photon is related to energy as

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p = hfc

p = hf/c

p = f(hc,f)

p = cf/h

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

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E = T²

E = -T²

E = T⁴

E = -T⁴

The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes

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2 mo

1.67 mo

0.67 mo

2.67 mo

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

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

Max plank received the Nobel Prize in physics for his discovery of energy quanta in

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1900

1906

1912

1918

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

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 existence of position was predicted by Dirace in

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1920

1925

1930

1928

A particle of mass 5.0 mg moves with a speed of 8.0 m/s. Its de-Brogile wavelength is

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1.66 m

1.66 x 10^-10m

1.66 x 10^-29cm

1.66 x 10^-29m

The special theory of relatively treats the problems involving:

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Inertial frames of reference

Non-inertial frames

Non-accelerated frame

Botha (A) and (C)

Both (B) and (C)

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 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

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

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

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

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

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