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	Energy required by an electron revolving in certain orbit to jump to an excited state is called:	A. Ionization energy B. Ionization potential C. Excitation energy D. Excitation potential
2	Gaussian surface is always:	A. Rectangular B. Spherical C. Cylinder D. Box shape
3	Selenium is:	A. An insulator B. A conductor C. Both A and B D. Excellent conductor
4	If the distance between two charges is doubled,the force between them will become:	A. Double B. Half C. One third D. One fourth
5	The value of the metastable state for Neon is	A. 20.66eV B. 20.61eV C. 19.23eV D. 18.70eV
6	The minimum wavelength of X-rays produced of 1KV potential difference is applied across the anode and cathode of the tube is	A. 1.24 x 10^-10m B. 7.92 x 10^-20m C. 2.78 x 10^-14m D. 3.88 x 10^-11m
7	The spectrum emitted from hydrogen filled discharge tube is:	A. Line spectrum B. Discrete spectrum C. And spectrum D. Absorption spectrum
8	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
9	The electric field lines start from:	A. Positive charge B. Negative charge C. Either A and B D. Neutron
10	Photons must have energy equal to	A. ev B. En C. hf D. None of these