A. Heating the filament
B. Electron excitation in the gas
C. Ionization of atoms
D. All the above
Related Mcqs:
- Radiation produced from TV picture tube is_____________?
A. B-rays
B. X-rays
C. Far infrared
D. Infrared - Radiation with wavelength longer than red lights______________?
A. ultraviolet rays
B. X-rays
C. infra red radiation
D. visible radiation - Which one of the following radiation possesses maximum penetrating power ?
A. X-rays
B. B-rays
C. γ-rays
D. All have the equal penetrating powe - If the wavelength of incident radiation is increased in photoemission then_________________?
A. The maximum kinetic energy of the photoelectrons increases
B. The minimum kinetic energy of the photoelectrons decreases
C. The minimum kinetic energy of the photoelectrons increases
D. The average kinetic energy of the photoelectrons decreases - Wave-like characteristic of electron is demonstrated by______________?
A. Line spectrum of atoms
B. Production of x-rays.
C. Diffraction by crystalline solids
D. Photoelectric effect - The direction of the vector product is given by______________?
A. Head to tail rule
B. Right-hand rule
C. Left-hand rule
D. Triangular rule - When a body is whirled in a horizontal circle by means of a string the centripetal force is supplied by______________?
A. Mass of a body
B. Velocity of body
C. The tension in the string
D. Centripetal acceleration - In case of planets the necessary acceleration is provided by______________?
A. Gravitational force
B. Frictional force
C. Coulomb force
D. Centripetal force - The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be______________?
A. 6.2 x 10-10m
B. 9.1 x 10-18m
C. 3.11 x 10-10m
D. 4 x 10-10m - In He-Ne laser the lasing action is produced by_______________?
A. Ne only
B. He-Ne both
C. Electrons of He
D. Electrons Ne
