ECAT Pre Computer Science Chapter 20 MCQ Test With Answer

Top Scorers Of ECAT Physics Chapter 20 Atomic Spectra MCQ`s Test

Sr.#	Question	Answer
1	Balmer series was identified in:	A. 1685 B. 1785 C. 1885 D. 1985
2	The range of wavelengths of colurs in the visible colours is	A. 140 nm to 456 nm B. 10 nm to 56 nm C. 410 nm to 656 nm D. 910 nm to 956 nm
3	Braking radiation causes:	A. Continuous spectrum B. Line Spectrum C. Band spectrum D. Discrete specturm
4	An compared to solid matter, a crack or an air bubble allows:	A. Great amount of X-rays to pass B. Smallast amount of X-rays to pass C. Very samall amount of X-rays to pass D. Any of these
5	The life time of metastable state is equal to	A. Life time of excited state B. Greater than by excited state C. Zero D. Less than by excited state
6	Selenium is:	A. An insulator B. A conductor C. Both A and B D. Excellent conductor
7	The results of spectra obtained by Blamer were expressed in 1896 by	A. Bohr B. Rydberg C. Planck D. Rutherford
8	The holes created in the L and M shells are occupied by transitions of:	A. Electrons from lower states B. Electrons from higher state C. Positrons from higher states D. Electrons from K shell
9	Tick the series which lies in the visible region:	A. Lyman series B. Balmer series C. Paschen series D. Brackett series
10	In case of braking radiations, when the rate of deceleration is very large, the emitted radiation corresponds to:	A. Short wavelength B. Large wavelength C. Very large wavelenth D. Low frequency