ECAT Pre Engineering Physics Chapter 20 MCQ Test With Answer

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

Sr.#	Question	Answer
1	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
2	We can excite an atom by	A. Bombardment of particles B. Radiating photons C. Providing potential difference D. All answer are true
3	The lasing or active medium in He-Ne laser discharge tube is:	A. Nitrogen B. Helium C. Hydrogen D. Neon
4	Spectrum represents the number of component colours present in certain light in terms of:	A. Wavelength B. Frequency C. Energy D. Both (A) and (B)
5	Photons must have energy equal to	A. ev B. En C. hf D. None of these
6	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
7	The first shell near the neucles is	A. L-shell B. X-shell C. N-shell D. M-shell
8	By CAT scans, we can detect the density difference of the order of:	A. 1% B. 20% C. 30% D. 50%
9	The spectrum emitted from hydrogen filled discharge tube is:	A. Line spectrum B. Discrete spectrum C. And spectrum D. Absorption spectrum
10	X-rays produced in a tube operating at 10⁵V. The speed of X-rays produced is	A. 3 x 10⁸m/s B. 3.1 x 10⁸m/s C. 2.8 x 10⁸m/s D. 1.88 x 10⁸m/s