ECAT Pre Engineering Physics Chapter 19 MCQ Test With Answer

Top Scorers Of Physics ECAT Pre Engineering Chapter 19 Dawn of Modern Physics MCQ`s Test

Sr.#	Question	Answer
1	If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be	A. 2.120°A B. 0.212°A C. 21.2°A D. 0.14° a
2	The unit of work function is:	A. Joule B. Electron volt C. That of threshold frequency D. Both (A) and (B)
3	The concept of direction and position are purely	A. absolute B. relative C. absolute or relative D. none of these
4	A non-inertial frame of reference is one, in which	A. law of inertial is valid B. all laws of physics are the same in all frames C. a>0 or a<0 D. a=0
5	When low energy photon interact with a metal,which of the following effect is likely to be taken place	A. pair production B. photoelectric C. Compton effect D. None of these
6	The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes	A. 2 mo B. 1.67 mo C. 0.67 mo D. 2.67 mo
7	Newton's law of motion do not hold in	A. an accelerated frame of reference B. an unaccelerated frame of reference C. both of these D. none of these
8	Compton derived an expression to find compton shift by applying to the process, the law of conservation of:	A. Energy only B. Momentum only C. Mass only D. Charge only
9	Momentum is a parameter associated with	A. wave motion B. particle motion C. neither wave nor particle motion D. none of these
10	The photon of radio-waves has energy of about	A. 1 Me V B. 1 Ke v C. 10^-10e v D. 10¹⁰e v