321. Reverse process of photoelectric effect is_______________?
A. pair production
B. Compton effect
C. annihilation of matter
D. X-rays production
322. Radiation with wavelength longer than red lights______________?
A. ultraviolet rays
C. infra red radiation
D. visible radiation
323. In an electronic transition atom cannot emit______________?
B. Infra red radiation
C. Visible light
D. Ultraviolet rays
324. X-rays are similar in nature to_______________?
A. Cathode rays
B. Positive rays
D. Beta rays
325. When X-rays are passed through successive aluminum sheets what happens to their thickness ?
B. it decreases
C. it remains same
D. sometimes increases and sometimes decreases
326. Quality of X-rays depends upon ____________ A-filament current B-accelerating voltage C-material of the target ?
A. A & B
B. B & C
C. A & C
D. A B & C
327. In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is_______________?
D. impossible to predict
328. Radiation produced from TV picture tube is_____________?
C. Far infrared
329. The minimum wavelength of X-rays can further be reduced by _______________?
A. Reducing the pressure or cooling the target
B. Increasing the temperature of the filament.
C. Using a target element of higher atomic number
D. Increasing the potential difference between the cathode and the target
330. The characteristic X-rays spectrum is due to_____________?
A. The illumination of the target metal by ultra-violet radiation
B. The bombardment of the target by protons
C. The bombardment of target by electrons
D. The absorption of radiation by the target metal