ECAT Pre Computer Science Chapter 19 MCQ Test With Answer

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

Sr.#	Question	Answer
1	At the temperature, a body emits radiation which is principally	A. of long wavelengths in the visible region B. of long wavelengths in the invisible infrared region C. of short wavelength in invisible ultraviolet region D. none of these
2	The Stephen-Boltzmann law for the black body radiation is given by	A. E = T² B. E = -T² C. E = T⁴ D. E = -T⁴
3	Due to relative motion of observer and the frame of reference of events, time always:	A. Dilates itself B. Contracts itself C. Stretches itself D. Both (A) and (C)
4	The inside cavity of the black body is	A. painted white B. painted silver C. blackened with soot D. painted red
5	When a platinum wire is heated, it appears white at	A. 1600°C B. 900°C C. 1100°C D. 1300°C
6	Intensity of light determines the:	A. Energy of each photon B. Number of photons C. Speed of photons D. Size of photons
7	The value of the plank's constant 'h' is given by	A. 1.6 x 10^-19J B. 1.67 x 10^-27Kg C. 6.63 x 10³⁴Js D. 6.63 x 10^-34Js
8	A black body is	A. an ideal absorber B. an ideal radiator C. both of them D. none of them
9	The speed of a pendulum is measured to be 3.0 s in the inertial reference frame of the pendulum. What is its period measured by an observer moving at a speed of 0.95 c with respect to the pendulum	A. 2.9 s B. 3.0 s C. 6.6 s D. 9.6 s
10	Momentum is a parameter associated with	A. wave motion B. particle motion C. neither wave nor particle motion D. none of these