Physics MCQs Quiz for Competitive Exams.This post contains Physics Objective Questions and Answers for NTS, PPSC, CSS, FPSC, PMS, OTS, PTS Tests and Interviews. These Objective Physics Questions and Answers are to prepare online competitive exams. MCQs are taken from Caravan Comprehensive GK Book.
1. A magnet freely suspended by means of a string will always set itself in which of the following directions ?
2. Why are shields made of iron usually provided around precision instruments ?
(a) For protection against the effect of external magnetic fields
(b) For guarding the instruments against unauthorised handling
(c) For protection against the effect of moisture in the air
(d) For absorbing heat generated during the functioning of the instrument
3. Why are transformers used in the transmission of electric power ?
(a) Because they speed up the transmission
(b) Because they can conserve electrical energy
(c) Because they can reduce transmission losses
(d) Because they help to distribute electrical energy efficiently
4. A mixture of which of the following gases is used in the manufacture of electric bulbs ?
(a) Nitrogen and Argon
(b) Nitrogen and Oxygen
(c) Oxygen and Argon
(d) Oxygen and Hydrogen
5. A fresh egg sinks in pure water, whereas it floats in saturated salty water. This is due to _______ ?
(a) Higher density of the salty water
(b) Higher density of the pure water
(0) The fluid matter inside the egg-shell
(d) The fact that the egg-shell is made of calcium which is heavier than pure water
6. Which one of the following is not an advantage of three phase system of the electric power supply over one phase system ?
(a) The output voltage is higher
(b) The power consumption is less
(c) The total output is almost constant
(d) The output of a 3-phase machine is greater than that of a single phase machine
7. Ball bearings are used to reduce friction by ?
(a) Applying lubricants to the balls used
(b) Reducing the area of contact with the use of metallic balls
(c) Increasing the area of contact with the use of metallic balls
(d) None of these
8. An electric motor runs on which principle ?
(3) Electrical energy can be converted into chemical energy in the presence of magnetic fields
(b) A conductor carrying current in the direction perpendicular to the external magnetic field feels a force
(c) The current flowing through a conductor causes generation of heat that drives the engine
(d) Changing magnetic field induces an electromotive force in a conductor
9. Which of the following functions is performed by a photocell ?
(a) It converts chemical energy into electrical energy
(b) it converts magnetic energy into electrical energy
(c) It converts light energy into electrical energy
(d) It converts electrical energy into light energy
10. Electronics is the study of ________ ?
(a) Flow of molecules
(b) Flow of electrons
(c) Flow of photons
(d) All are true
11. Which of the following gives the correct descending order of elasticity in the substances ?
(a) Rubber, silver, glass
(b) Silver, rubber, steel
(c) Steel, silver, rubber
(d) All have equal elasticity
12. Which of the following colour of light travel through, glass with minimum speed ?
13. A Polaroid is _____ ?
(a) A red light filter
(b) A device used for analysing polarized light
(c) A device used in the polarimeter
(d) An adjustable shutter
14. When a beam of light is passed through a transparent medium, however clear or homogeneous the medium may be, there is always a certain amount of light scattered sideways, out of the beam. This is known as _______ ?
(a) Rayleigh scattering
(c) Raman effect
(d) None of the above
15. The phenomenon of land and sea breeze is as a result of _______ ?
(d) None of these