Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
1. Which among the following is true about Total Internal Reflection?
[A] A ray passing from rarer to denser medium and not able to pass to denser medium at an angle greater than critical angle
[B] A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle
[C] A ray passing from either denser to rarer medium or rarer to denser medium and not able to pass any medium at an angle smaller than critical angle
[D] None of the above
Show Answer
Correct Answer: B [A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle]
Notes:
A ray passing from denser to rarer medium and not able to pass to rarer medium at an angle greater than critical angle. Critical angle is the angle in which the incident ray is 90 degrees to that of the refracted ray.
2. Newton-meters per second is represented as follows?
[A] Ohm
[B] Volt
[C] Watt
[D] Calorie
Show Answer
Correct Answer: C [Watt]
Notes:
one watt is the rate at which work is done when an object is moved at a speed of one meter per second against a force of one Newton.
3. Crystals of which of the following naturally-occuring substance exhibits both ‘pyroelectric’ and ‘piezoelectric’ properties making it versatile for application in the field of electronics?
[A] Quartz
[B] Mica
[C] Topaz
[D] grapite
Show Answer
Correct Answer: A [Quartz]
Notes:
Quartz crystals have piezoelectric properties: they develop an electric potential upon the application of mechanical stress. An early use of this property of quartz crystals was in phonograph pickups. A common piezoelectric use of quartz today is as a crystal oscillator. The quartz clock is a familiar device using the mineral. Quartz is also strongly pyroelectric. Temperature changes create positive and negative charges within the crystal.
4. Two pieces of ice at 0°C would freeze together if pressed against each other and then released. In this context, which among the following is the correct principle in action in this?
[A] The melting point of pure ice decreases with pressure.
[B] The melting point of pure ice increases with Pressure
[C] The melting point of pure ice first increases, then decreases with pressure
[D] The melting point of pure ice first decreases then increases with pressure
Show Answer
Correct Answer: A [ The melting point of pure ice decreases with pressure.]
Notes:
Melting point of pure ice decreases with pressure at the rate of 0.0072°C per atmosphere and this is called regulation, which was discovered by Faraday and occurs at some 0°C or very slightly less temperature.
5. On heating a pure silicon circular disc with a circular hole at the centre, the diameter of the hole:
[A] will expand
[B] will contract
[C] will remain constant
[D] may expand or contract
Show Answer
Correct Answer: B [ will contract]
Notes:
Pure silicon has a negative coefficient of thermal expansion for temperatures and hence it shows contraction effect.
6. Who gave the Theory of Relativity?
[A] Isaac Newton
[B] Archimedes
[C] Albert Einstein
[D] Galileo Galilei
Show Answer
Correct Answer: C [Albert Einstein]
Notes:
Albert Einstein was the founder of Theory of Relativity. According to Einstein’s theory, mass m is equivalent to energy E given by the relation E = mc^2 where c is speed of light in vacuum. Albert Einstein was awarded the 1921 Nobel Prize in Physics for his contribution to the field of Theoretical Physics.
7. Who among the following is credited to work for the unification of electricity, magnetism and optics field of Physics?
[A] James Clerk Maxwell
[B] Michael Faraday
[C] Haris Christian Oersted
[D] Isaac Newton
Show Answer
Correct Answer: A [James Clerk Maxwell]
Notes:
James Clerk Maxwell made the efforts for the unification of electricity, magnetism and optics field of Physics. He showed that light is an electromagnetic wave. James Clerk Maxwell was a Scottish mathematician, physicist and is known best for his mathematical work on electromagnetism and on the behaviour of gases.
8. The branch of mechanics which deals with the study of motion of material objects without taking into account the factors which cause motion is called as:
[A] Statics
[B] Kinematics
[C] Dynamics
[D] None of the above
Show Answer
Correct Answer: B [Kinematics]
Notes:
The branch of mechanics which deals with the study of motion of material objects without taking into account the factors which cause motion is called as Kinematics. The branch of mechanics which deals with the study of motion of material objects taking into account the factors which cause motion is called as Dynamics. The branch of mechanics which deals with the study of material objects at rest is called as Statics.
9. Two satellites, A having mass of 500 kgs and B having mass of 1200 kgs, are launched from earth. Which of these will have a greater orbital velocity if the radius of orbit is same for both?
[A] Satellite A
[B] Satellite B
[C] Both satellites will have the same orbital velocity
[D] Cant be determined
Show Answer
Correct Answer: C [Both satellites will have the same orbital velocity]
Notes:
Both satellites will have the same orbital velocity as the orbital velocity of a satellite is independent of mass of satellite.
10. Which of the following relations between Kinetic energy and Potential energy is true about solids?
[A] Kinetic energy = Potential energy
[B] Kinetic energy > Potential energy
[C] Kinetic energy >> Potential energy
[D] Kinetic energy < Potential energy
Show Answer
Correct Answer: D [Kinetic energy < Potential energy]
Notes:
In Solids, Kinetic energy is always less than the Potential energy. For liquids, Kinetic energy > Potential energy. For Gases, Kinetic energy >> Potential energy.
