Atomic Physics interview questions

Electrons revolving in stationary orbits

1. sometimes radiate energy
2. radiates very less energy
3. radiates enormous amount of energy
4. does not radiate energy

Wavelength of X-rays depends upon

1. kinetic energy of the electrons producing them
2. the number of electrons striking the target
3. thickness of the target material
4. the target material used

Optical pumping is used to produce

1. Normal population
2. UV-radiation
3. IR radiation
4. Population inversion

According to electromagnetic theory, an accelerated electric charges radiates energy in the form of

1. electromagnetic waves
2. sound waves
3. nuclear energy
4. atomic energy

A secondary photon is _____ with the stimulating photon.

1. sometimes out of phase
2. sometimes in phase
3. always in phase
4. always out of phase

Who suggested that an atom is a sphere of positive charge and electrons are embedded in it?

1. J.J. Thomson
2. Rutherford
3. Dalton
4. Prout

A photon produced by stimulated emission is called _____ photon.

1. primary
2. secondary or stimulated
3. stimulated
4. secondary

When cathode rays pass through the gas, they

1. neutralise the gas
2. condense the gas
3. compress the gas
4. ionise the gas

The charge of helium atom is equal to

1. twice the charge of an electron
2. charge of positron
3. charge of electron
4. charge of proton

_____ are used as MASER materials.

1. Diamagnetic ions
2. Ferromagnetic ions
3. Paramagnetic ions
4. All the above

Dalton showed that the matter is made up of extremely small particles called ____

1. Atoms
2. Quarks
3. Nuclei
4. Molecules

____ quantum number is useful in finding the possible elliptical orbits.

1. Spin
2. Magnetic
3. Orbital
4. Principle

Canal rays travel in ____

1. Curved paths
2. Parabolic paths
3. Straight lines
4. Circular paths

The charge possessed by the canal rays is ___

1. Neutral charge
2. Negative charge
3. Positive charge
4. Both (a) and (b)

The study of electric discharge through gases gives valuable information regarding the structure of ___

1. Molecules
2. Atom’s
3. Nucleus of an atom
4. Molecules and atoms

According to Rutherford atom model, the spectral lines emitted by an atom is ___

1. Band spectrum
2. Continuous absorption spectrum
3. Continuous spectrum
4. Line spectrum

Cathode rays are ___

1. Protons
2. Neutrons
3. Positrons
4. Electrons

Charge per unit mass measures ___ of the particle.

1. Charge density
2. Specific mass
3. Specific charge
4. Specific density

The magnetic Lorentz force experienced by the electron in the magnetic field is ____

1. Mev
2. Ee
3. Bev
4. B2v

____ is used to detect and measure the intensity of X-rays.

1. Detector
2. Vacuum chamber
3. Ionization chamber
4. None of the above

____ are produced at high potential difference in Coolidge tube.

1. Hard X-rays
2. Positive rays
3. Soft X-rays
4. Cathode rays

____ is used to vapourize the unwanted material during the manufacture of electronic circuit on semiconductor chips.

1. Positive rays
2. Laser beams
3. Radioactive rays
4. Cathode rays

The crystal that was used in Laue experiment to diffract X-rays was ___ crystal.

1. Copper sulphate
2. Calcium carbonate
3. Zinc sulphide
4. Ammonium nitrate

Which atom model explains the fine structure of spectral lines?

1. Sommerfeld atom model
2. Thomson atom model
3. Bohr’s atom model
4. Rutherford atom model

Millikan’s experiment determines ___

1. Mass of an electron
2. Charge density of an electron
3. Charge of an electron
4. Specific charge of an electron

The energy of a photon of characteristics X-ray from a Coolidge tube comes from ___

1. An atomic transition in the target
2. The kinetic energy of the striking electron
3. The kinetic energy of ions of the target
4. The kinetic energy of the free electrons of the target

Canal rays are produced at a pressure of ______ of mercury.

1. 1 mm
2. 0.01 mm
3. 10 mm
4. 0.01 mm

Cathode rays possess ___

1. Momentum
2. Kinetic energy
3. Potential energy
4. Both (a) and (b)

The electric current passes through a gas column if the applied potential difference is ___

1. Small and the pressure is high
2. Small and the pressure is low
3. Large and the pressure is low
4. Large and the pressure is high

____ is the device used in discharge tube to maintain a high potential difference.

1. DC generator
2. Induction coil
3. AC generator
4. Transformer