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	A bar 1.0 m in length and located along x-axix moves with a speed of 0.75 c with respect to a stationary observer. The length of the bar as measured by the stationary observer is	A. 1.66 m B. 1.0 m C. 0.66 m D. 2.66 m
2	A high temperature, the proportion of shorter wavelengths radiation, emitted by the body	A. decreases B. first increases then decreases C. increases D. any one of them
3	The ratio of energy E to the corresponding frequency (f) of the radiation (emitted or absorbed) is called:	A. Wien's constant B. Stefen's constnat C. Planck's constant D. Boltzmann's constant
4	Position was discovered by Carl Anderson in	A. 1920 B. 1925 C. 1928 D. 1932
5	Which one of the following physical quantities changes with relativistic speed	A. Length B. Mass C. Time D. All of the above
6	The special theory of relativity is based on the	A. one postulate B. two postulates C. three postulates D. four postulates
7	When the atomic particle are moving with velocities approaching that of light:	A. Newton's laws become valid B. Relativistic effects become prominent C. Botha(A) and (B) are valid D. Neither (A)nor (B)
8	An inertial frame is that frame in which	A. a>0 B. a=0 C. a<0 D. none of these
9	The value of the Stephen's constant for black body radiations is given by	A. 5.6 x 10⁸Wm^-2K^-4 B. 5.67 x 10^-8Wm^-2K^-4 C. 2.9 x 10^-3mK D. 2.9 x 10³mK
10	The concept of direction and position are purely	A. absolute B. relative C. absolute or relative D. none of these