Modern Physics interview questions

Cathode rays enter an electric field normal to the lines of force. Then their path in the electric field is

1. Parabola
2. Straight line
3. Circle
4. Ellipse

Cathode rays can be deflected by

1. Magnetic field
2. Electric fields
3. Both electric and magnetic fields
4. None of the above

The velocity of photo electron emitted in photoelectric effect depends only on

1. The wave length of incident light
2. The frequency and intensity of incident light
3. The frequency of incident light
4. None of these

An atom bomb is based upon the principle of

1. Controlled nuclear fission
2. Nuclear fusion
3. Nuclear fission
4. None of the above

The mass defect per nucleon is called

1. Binding energy
2. Packing fraction
3. Ionization energy
4. Excitation energy

Nuclear forces are

1. Attractive or repulsive depending upon separation between nucleons
2. Neither attractive nor repulsive
3. Attractive only
4. Repulsive only

The fourth state of matter is known as

1. Electrons
2. Gas
3. Vapour
4. Plasma

If a U-238 nucleus splits into two identical parts, the two nuclei so produced will be

1. Radioactive
2. Stable
3. Isobars
4. Isotopes

Which of the particles has similar mass to that of the electron?

1. Neutrino
2. Positron
3. Neutron
4. Proton

The ratio of specific charges of an alpha particle to that of a proton is

1. 1/2
2. 1/3
3. 1/1
4. 2/1

The cause of fractional atomic weights of elements is the presence of

1. Isotones
2. Isobars
3. Isotopes
4. None of these

Voltage applied between the electrodes of discharge tube is of the nature

1. Voltage obtained by induction coil
2. 220 V alternating voltage
3. 220 V DC voltage
4. Variable voltage

The mass energy relation is the outcome of

1. Special theory of relativity
2. Quantum theory
3. Field theory of relativity
4. General theory of relativity

The first explosion of an atomic device in India was carried out in the state of

1. Rajasthan
2. Jammu and Kashmir
3. Manipur
4. Nagaland

Which of the following will deflect in electric field?

1. X-rays
2. Y-rays
3. Ultraviolet rays
4. Cathode rays

The ionisation energy of sodium in KJ per mole is

1. 496
2. 596
3. 4632
4. 5926

In nuclear fission, the percentage of mass converted into energy is about

1. 10%
2. 0.01%
3. 0.1%
4. 1%

If alpha, beta and gamma rays carry same momentum, which has the longest wavelength?

1. Gamma rays
2. Alpha rays
3. Beta rays
4. None, all have same wavelength

When the speed of electrons increases, then the value of the specific charge on an electron

1. Increases
2. Decreases
3. Remains unchanged
4. None of these

Nuclear forces are mediated by

1. Proton
2. Neutron
3. Meson
4. Electron

The fuel used in nuclear power plants is

1. U-235
2. U-236
3. U-238
4. U-239

An atomic pile is used for

1. Temperature
2. Conducting nuclear fission
3. Conducting thermonuclear fission
4. Producing X-rays

Isotopes have the same

1. Atomic number
2. Mass number
3. Avogadro’s number
4. None of these

A good moderator should

1. Not be a gas only
2. Not have appetite for neutrons only
3. Be light in mass number only
4. Be all above three

The dual nature of light is exhibited by

1. Diffraction and photoelectric effect
2. Diffraction and reflection
3. Refraction and interference
4. Photoelectric effect

The main source of solar energy is

1. Combustion
2. Nuclear fission
3. Nuclear fusion
4. None of these

The important conclusion given by Millikan’s experiment about the charge is

1. Charge is never quantized
2. Charge has no definite value
3. Charge is quantized
4. Charge on oil drop always increases

Neutron was discovered by

1. Rutherford
2. James Chadwick
3. J.J. Thomson
4. Henry Becquerrel

In nuclear reaction, there is conservation of

1. Mass only
2. Energy only
3. Mass energy and momentum
4. Momentum only

Hydrogen bomb is based upon the principle of

1. Controlled nuclear fission
2. Nuclear fission
3. Nuclear fusion
4. None of the above