# Atomic Spectra 12 Class Physics MCQs

FSC Physics MCQs Part 1 Physics Part 2 HSSC Pre Medical Pre Engineering text Book Questions first year and second-year Physics mcqs

Photon of highest frequency will be absorbed when transition takes place from
A. 1st to 5th orbit B. 2nd to 5th orbit
C. 3rd to 5th orbit D. 4th to 5th orbit
A
In obtaining an X-ray photograph of our hand we use the principle of
A. photo electric effect B. ionization
C. shadow photograph D. any of above
C
When we excite some atoms by heat collision or electrical discharge they will
A. radiate electromagnetic energy with a continuous distribution of wavelength
B. absorb particular wavelengths when white light is incident on them
C. radiate electromagnetic energy of discrete characteristic wavelength
D. emit either invisible or visible light
C
Tick the correct statement
A. an atom has limited number of ionization potentials but a large number of excitation potentials
B. there are as many excitation potentials as there are excited states
C. the difference between the energy of the ground sate and any one of the excited states is the measure of excitation energy
D. all of above
D
Radiation with wavelength longer than red lights
A. ultraviolet rays B. X-rays
C
Reverse process of photoelectric effect is
A. pair production B. Compton effect
C. annihilation of matter D. X-rays production
D
The penetrating power of X-rays depends on their
A. applied voltage B. frequency
C. source D. all of the above
B
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
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
A
Maximum frequency in the spectrum from X-ray tube is directly proportional to the
A. Number of incident electron i.e. filament current.
B. The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.
C. The soft target which can easily emit electrons.
D. all of above are correct.
B

Salam