Question # 1

A device used to determine mass of an isotope quite accurately is known as.

Choose an answer

Spectrometer

Mass spectrometer

Mass detector

Electronic balance

The absorption of X-rays in a given material follows.

Choose an answer

A parabola path

Is straight line

An exponential curve

A circle

Which of the following is the most commonly used regions of operations for a transistor.

Choose an answer

Cut off

Saturation

Active

All of these

In scattering experiment which force scatters alpha particle.

Choose an answer

Nuclear force

Coulomb's force

Gravitational force

Centripetal force

Positron are produced during.

Choose an answer

Annihilation

ionization

Pair production

x rays production

The half life of uranium -238 is

Choose an answer

1620 years

4.5 x 10⁹years

3-8 days

23.5 minutes

The potential due to which an electron is lifted from gerund state to excited state is.

Choose an answer

Potential gradient

excitation potential

Ionization potential

Potential difference

For an electron or position the rest mass energy is equal to.

Choose an answer

0.21 MeV

0.51 MeV

1.51 MeV

1.21 MeV

The reciprocal of decay constant lamda of a radioactive substances is equal to.

Choose an answer

total life

Half life

Mean life

Curie

Cs - 137 is a radioisotope used ot determine the thickness of the walls of steel pipes Cs 137 is chosen because it emits

Choose an answer

Radiowaves

Alpha particles

Beta particles

gama particles

When we pass a radiation from a radioactive material through an electric field.

Choose an answer

All three kinds of rays will be deflected

Only the Gama rays are deflected

The Alpha and Beta particles are deflected

Only the alpha particles are deflected

X-rays spectrum may be

Choose an answer

Continuous spectrum

Discontinuous spectrum

Line spectrum

Continuous and line spectrum

In n-p-n transistor the current flows in the direction from

Choose an answer

Emitter to base

emitter to collector

Base to emitter

Base to collector

The radius of second orbit of hydrogen atom is

Choose an answer

0.071 A

0.142 A

4.752 A

9.5298 A

Alpha particles emitted from a radioactive material are.

Choose an answer

He nucliei

H -nucliei

Li nucliei

B nucliei

The path of Gama rays in Wilson cloud chamber is

Choose an answer

Irregular

Dense and straight

Thin and continuous

Thin and discontinuous

The emission of photons by a metal when electrons are incident is called.

Choose an answer

Photo electric effect

Pair production

X-rays production

Gama ray production

During transition, atom cannot emit

Choose an answer

Visible light

Ultraviolet radiation

Infrared radiations

gama rays

The Compton effect in X-rays proves that

Choose an answer

Electrons have wave property

x-rays have wave properly

X-rays have particle characteristics

Electrons cannot exist

Which of the following propagates at the same speed as velocity of light.

Choose an answer

Heat waves

Sound waves

Shock waves

Beta particles

Transistors with various combinations are widely used as switches in.

Choose an answer

electric generators

Rectificers

Amplifiers

Computers

More Classes

Other Links

PPSC Physics Chapter 7 Modern Physics 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

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer