Question # 1

If a body reaches a speed equal to the speed of light, then its mass will became

Choose an answer

zero

very small

infinity

none of these

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

Choose an answer

2 mo

1.67 mo

0.67 mo

2.67 mo

Compton was awarded Nobel prize in physics in

Choose an answer

1921

1923

1925

1927

Photocell is a device which converts

Choose an answer

chemical energy into electrical energy

electrical energy into light energy

heat energy into electrical energy

light energy into electrical energy

the dilation of time applies to the timing processes which are:

Choose an answer

Physical

Chemical

Biological

All of these

None of these

The photon of radio-waves has energy of about

Choose an answer

1 Me V

1 Ke v

10^-10e v

10¹⁰e v

Position and momentum of a particle cannot both be measured simultaneously with perfect accuracy. This is the statement of

Choose an answer

photoelectric effect

pair production

Compton effect

uncertainty principle

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

Choose an answer

classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

The value of threshold frequency for different metals is

Choose an answer

different

same

may be different or may be same

none of these

Electromagnetic -radiation means:

Choose an answer

Photons

protons

Electrons

Mesons

None of these

Davision and Germer performed experiment to verify

Choose an answer

de-Brogile hypothesis

theory of relativity

Newton's law of gravitation

Mass-energy relation

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

Choose an answer

p = hfc

p = hf/c

p = f(hc,f)

p = cf/h

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

Choose an answer

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:

Choose an answer

Newton

Joule

Joule-Sec

Joule-s^-1

Watt

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

Choose an answer

Wien's constant

Stefen's constnat

Planck's constant

Boltzmann's constant

None of these

More Classes

Other Links

Physics ECAT Pre Engineering Chapter 19 Dawn of Modern Physics Physics Online Test MCQs With Answers

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer