A. its energy levels are too close to each other
B. its energy levels are too far apart
C. it is too small in size
D. it has a single electron
Related Mcqs:
- Two sources of light are coherent if they emit rays of_______________?
A. same wavelength
B. same amplitude of vibration
C. same wave length with constant phase difference
D. same amplitude and wavelength - T.V sets and microwave ovens emit ___________________?
A. X-rays
B. α-rays
C. β-rays
D. γ-rays - The penetrating power of X-rays depends on their______________?
A. applied voltage
B. frequency
C. source
D. all of the above - X-rays are similar in nature to_______________?
A. Cathode rays
B. Positive rays
C. γ-rays
D. Beta rays - When X-rays are passed through successive aluminum sheets what happens to their thickness ?
A. increases
B. it decreases
C. it remains same
D. sometimes increases and sometimes decreases - 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 - 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_______________?
A. he/ev
B. he/Vc
C. eV/h
D. impossible to predict - 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 - 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 - X-rays are diffracted by a crystal but not by a diffraction grating because_____________?
A. The ions in a crystal are well arranged
B. The lines in a diffraction grating cannot reflect X-rays.
C. The penetration power of X-rays is high in a diffraction grating
D. The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal
