Question # 1

LED is a p-n junction that emits

Choose an answer

Visible light

X- rays

Ultraviolet light

electromagnetic waves

The minimum amount of energy in an individual electron has to gain to escape from a particular surface is called.

Choose an answer

Threshold frequency

work function

Wave number

Kinetic energy

Nuclear force exists between

Choose an answer

Proton proton

Neutron -neutron

neutron -proton

All of these

The process of conversation of a photon into an electron and a position is called.

Choose an answer

Pair annihilations

Pair production

Photoelectric effect

Compton effect

Mosley's law establishes the X-rays fluorescence of target element with is.

Choose an answer

Atomic weight

Atomic number

Density

Lattice constant

What is the relativistic version of the Schrodinger equation.

Choose an answer

Klein Gordon equation

Laplace equation

Quadratic equation

Binomial equation.

For the normal operation of transistor the emitter base junction is always.

Choose an answer

Zero biased

Reverse biased

Forward bised

Both a and b

When transistor works as an amplifier, its output is.

Choose an answer

More

Less

Zero

Directly proportional to the input

An oscillator is basically an amplifier with loop gain

Choose an answer

Zero

Less than unity

More than unity

Infinity

Bohr's atomic model assumes

Choose an answer

Nucleus is of infinite mass and is at rest

electron in a quantized orbit will not radiate energy

Mass of electron remains the same

All of the above

What is the overall gain, if three amplifiers each with a gain of 30 are cacaded.

Choose an answer

30

90

270

27,000

When light of particular frequency is allowed to fall upon a metal surface electrons are emitted from a these emitted electrons are called.

Choose an answer

Photons

Holes

Quants

Photo electrons

Compton scattering experiment seemed to indicate that radiation had

Choose an answer

Wave nature

Particle nature

Wave particle nature

X-rays nature

Which particles have spin quantum number 1/2

Choose an answer

Mesons

Laptons

Hadrons

Muons

During the alpha decay process

Choose an answer

A neutron is emitted

a electron is emitted

A helium core is emitted

A proton core is emitted

Tracer techniques make use of.

Choose an answer

Neutron scattering

Electron beams

LASER

Radioactive isotopes

Which of the following is the most massive particle.

Choose an answer

Deuteron

Alpha particle

Neutron

positron

The transition of inner shell electrons in heavy atoms gives rise to the emission of.

Choose an answer

Low energy b-particle

High energy b-particle

High energy X- rays

High energy gama rays

Which one of the following spectra series is in the ultraviolet region.

Choose an answer

Lyman series

Paschen series

Brackett series

Plund series

The particles equal in mass or greater than protons are called.

Choose an answer

Mesons

Bosons

Baryons

Nucleons

The energy of neutrons obtained during a fission reaction is.

Choose an answer

0.1 MeV

1 KeV

1 MeV

Zero

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