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	According to the special theory of relativity, time is	A. absolute quantity B. not absolute quantity C. constant quantity D. none of these
2	According to the special theory of relativity, a moving clock	A. runs faster B. runs slower C. neither runs faster nor slower D. all of these
3	When a position comes close to an electron they annihilate into photons such that	A. each photon has energy 0.51 Me v B. each photon has energy 1.02 Me v C. each photon has energy 0.25 Me v D. none of these
4	A particle having mass and charge equal to that of an electron is called:	A. Proton B. Positron C. Pion D. Pi-meson
5	If a body reaches a speed equal to the speed of light, then its mass will became	A. zero B. very small C. infinity D. none of these
6	The length contraction happens only	A. Opposite to the direction of motion B. along the direction of motion C. perpendicular to the direction of motion D. In any direction
7	Strictly speaking, the earth is:	A. An accelerated frame of reference B. A non-inertial frame of reference C. An inertial frame of reference D. ^{A non-accelerated frame of reference}
8	An electron is accelerated through a potential difference of 50v. its de-Brogile wavelength is	A. 1.66 x 10^-29m B. 1.74 x 10^-10cm C. 17.4 x 10^-6m D. 1.74 x 10^-10m
9	Electromagnetic -radiation means:	A. Photons B. protons C. Electrons D. Mesons
10	When a platinum wire is heated, it appears yellow at	A. 1600°C B. 900°C C. 1100°C D. 1300°C