100 General Science MCQs on Physics subject, which cover important topics that are frequently asked in competitive exams like UPSC, SSC, etc.
1. Mechanics (1-20)
What is the SI unit of force?
a) Watt
b) Newton
c) Joule
d) Ampere
Ans:
b) Newton
The principle of conservation of linear momentum is based on which of the following laws?
a) Newton's First Law
b) Newton's Second Law
c) Newton's Third Law
d) None of the above
Ans:
c) Newton's Third Law
What is the SI unit of work?
a) Watt
b) Joule
c) Newton
d) Ampere
Ans:
b) Joule
Which of the following is an example of scalar quantity?
a) Force
b) Velocity
c) Speed
d) Acceleration
Ans:
c) Speed
The velocity of an object is 10 m/s. If the object travels for 5 seconds, what distance will it cover?
a) 10 m
b) 25 m
c) 50 m
d) 100 m
Ans:
c) 50 m
Which of the following has the highest velocity in vacuum?
a) Sound wave
b) Light wave
c) Electromagnetic wave
d) All of the above
Ans:
b) Light wave
A body is in motion under the influence of a constant force. The velocity of the body increases uniformly. What is the nature of the motion?
a) Uniform motion
b) Uniformly accelerated motion
c) Non-uniform motion
d) None of the above
Ans:
b) Uniformly accelerated motion
The formula for acceleration is given by:
a) a = Δv / Δt
b) a = v * t
c) a = F / m
d) a = m * v
Ans:
a) a = Δv / Δt
Which of the following is a vector quantity?
a) Speed
b) Distance
c) Displacement
d) Time
Ans:
c) Displacement
What is the acceleration due to gravity on Earth?
a) 10 m/s²
b) 9.8 m/s²
c) 9.8 m/s
d) 9.8 m/s²
Ans:
b) 9.8 m/s²
The work done by a force is maximum when the force is applied at an angle of:
a) 0°
b) 45°
c) 90°
d) 180°
Ans:
a) 0°
The moment of inertia of a body depends on:
a) Shape of the body
b) Mass of the body
c) Distance of mass from the axis of rotation
d) All of the above
Ans:
d) All of the above
In a collision, if the kinetic energy is conserved, the collision is called:
a) Inelastic collision
b) Elastic collision
c) Partially elastic collision
d) None of the above
Ans:
b) Elastic collision
The pressure exerted by a liquid depends on:
a) Density of the liquid
b) Depth of the liquid
c) Gravitational pull
d) All of the above
Ans:
d) All of the above
In simple harmonic motion, the displacement of a body is given by:
a) x = A sin ωt
b) x = A cos ωt
c) x = A sin (ωt + φ)
d) All of the above
Ans:
d) All of the above
Which of the following is the unit of power?
a) Watt
b) Newton
c) Joule
d) Ampere
Ans:
a) Watt
Which of the following is an example of uniform circular motion?
a) Motion of a car on a straight road
b) Motion of the Moon around the Earth
c) Motion of a stone thrown upwards
d) All of the above
Ans:
b) Motion of the Moon around the Earth
The centripetal force on an object moving in a circular path is directed:
a) Towards the center of the circle
b) Away from the center of the circle
c) Tangential to the circle
d) None of the above
Ans:
a) Towards the center of the circle
Which of the following is the unit of acceleration?
a) m/s
b) m/s²
c) m
d) m²/s
Ans:
b) m/s²
The potential energy of an object depends on its:
a) Mass
b) Height
c) Gravitational field
d) All of the above
Ans:
d) All of the above
2. Thermodynamics (21-40)
The first law of thermodynamics is a statement of the law of conservation of:
a) Mass
b) Energy
c) Momentum
d) Motion
Ans:
b) Energy
The efficiency of a Carnot engine depends on:
a) Temperature of the cold reservoir
b) Temperature of the hot reservoir
c) Both of the above
d) Neither of the above
Ans:
c) Both of the above
What is the SI unit of temperature?
a) Kelvin
b) Celsius
c) Fahrenheit
d) Joule
Ans:
a) Kelvin
The heat required to raise the temperature of a substance is directly proportional to:
a) Its mass
b) Its specific heat capacity
c) The change in temperature
d) All of the above
Ans:
d) All of the above
In an adiabatic process, which of the following remains constant?
a) Pressure
b) Temperature
c) Heat
d) Volume
Ans:
c) Heat
The second law of thermodynamics deals with the concept of:
a) Energy conservation
b) Heat transfer
c) Entropy
d) Pressure
Ans:
c) Entropy
The specific heat capacity of water is:
a) 1 J/g°C
b) 4.18 J/g°C
c) 0.5 J/g°C
d) 0.2 J/g°C
Ans:
b) 4.18 J/g°C
The working substance in a heat engine absorbs heat and does work. This is an example of:
a) Isothermal process
b) Adiabatic process
c) Isobaric process
d) Isometric process
Ans:
b) Adiabatic process
The efficiency of a heat engine is always less than 100% due to:
a) Energy loss
b) Loss of heat to the surroundings
c) Entropy generation
d) All of the above
Ans:
d) All of the above
What is the absolute zero temperature?
a) -273°C
b) 0°C
c) 0K
d) 100°C
Ans:
c) 0K
Which of the following is a perfect example of an isothermal process?
a) Boiling of water
b) Heating a metal rod
c) Compression of gas at constant temperature
d) All of the above
Ans:
c) Compression of gas at constant temperature
The latent heat of fusion of ice is the heat required to:
a) Melt 1 kg of ice
b) Boil 1 kg of water
c) Freeze 1 kg of water
d) None of the above
Ans:
a) Melt 1 kg of ice
The specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of:
a) 1 kg of the substance by 1°C
b) 1 gm of the substance by 1°C
c) 1 gm of the substance by 1K
d) 1 kg of the substance by 1K
Ans:
a) 1 kg of the substance by 1°C
In a thermodynamic process, work is done by the system when:
a) Volume decreases
b) Volume remains constant
c) Volume increases
d) Pressure remains constant
Ans:
c) Volume increases
The change in internal energy of a system in an adiabatic process is equal to:
a) Heat added to the system
b) Work done by the system
c) Change in temperature
d) All of the above
Ans:
b) Work done by the system
In a Carnot engine, the efficiency depends on the temperatures of the:
a) Work done
b) Hot and cold reservoirs
c) System
d) Surroundings
Ans:
b) Hot and cold reservoirs
Which of the following processes occur at constant volume?
a) Isothermal process
b) Isobaric process
c) Isochoric process
d) Adiabatic process
Ans:
c) Isochoric process
Which of the following is the unit of heat?
a) Newton
b) Watt
c) Joule
d) Calorie
Ans:
c) Joule
The law of conservation of energy applies to which of the following?
a) Thermodynamics
b) Conservation of momentum
c) Friction
d) All of the above
Ans:
a) Thermodynamics
In a Carnot engine, what is the relationship between heat absorbed and work done?
a) Heat absorbed = Work done
b) Heat absorbed > Work done
c) Heat absorbed < Work done
d) Heat absorbed and work done are independent
Ans:
b) Heat absorbed > Work done
3. Optics (41-60)
The speed of light in vacuum is approximately:
a) 3 × 10⁸ m/s
b) 2 × 10⁸ m/s
c) 3 × 10⁶ m/s
d) 3 × 10⁹ m/s
Ans:
a) 3 × 10⁸ m/s
The angle of incidence is equal to the angle of reflection in:
a) Refraction
b) Reflection
c) Diffraction
d) Dispersion
Ans:
b) Reflection
The focal length of a convex lens is positive, while that of a concave lens is:
a) Positive
b) Negative
c) Zero
d) Infinite
Ans:
b) Negative
A concave lens always forms an image that is:
a) Real
b) Inverted
c) Virtual and erect
d) None of the above
Ans:
c) Virtual and erect
The refractive index of a medium is the ratio of:
a) Speed of light in air to the speed of light in the medium
b) Speed of light in the medium to the speed of light in air
c) Wavelength in the medium to the wavelength in air
d) None of the above
Ans:
a) Speed of light in air to the speed of light in the medium
The critical angle is the angle of incidence for which the angle of refraction is:
a) 90°
b) 0°
c) 45°
d) 180°
Ans:
a) 90°
What happens when light passes from a denser medium to a rarer medium?
a) The light bends towards the normal
b) The light bends away from the normal
c) No bending occurs
d) None of the above
Ans:
b) The light bends away from the normal
In a concave mirror, a real image is formed when the object is placed at:
a) Focus
b) Centre of curvature
c) Focal point
d) Any point
Ans:
b) Centre of curvature
Here are questions 49 to 80 on General Science – Physics (MCQs), continuing from where we left off.
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Here are questions 49 to 80 on General Science - Physics (MCQs), continuing from where we left off.
3. Optics (continued) (49-60)
The focal length of a concave mirror is:
a) Negative
b) Positive
c) Zero
d) Infinite
Ans:
a) Negative
Which of the following mirrors is used in vehicle side mirrors?
a) Concave mirror
b) Convex mirror
c) Plane mirror
d) None of the above
Ans:
b) Convex mirror
The splitting of white light into its constituent colors when passing through a prism is called:
a) Reflection
b) Refraction
c) Dispersion
d) Diffraction
Ans:
c) Dispersion
Which of the following optical phenomena is responsible for the blue color of the sky?
a) Reflection
b) Refraction
c) Scattering
d) Diffraction
Ans:
c) Scattering
The power of a lens is measured in:
a) Newton
b) Joule
c) Dioptre
d) Hertz
Ans:
c) Dioptre
A lens with a power of -2D is:
a) Convex lens
b) Concave lens
c) Cylindrical lens
d) None of the above
Ans:
b) Concave lens
Which of the following optical instruments uses two convex lenses?
a) Microscope
b) Telescope
c) Magnifying glass
d) Both a and b
Ans:
d) Both a and b
Which of the following has the highest refractive index?
a) Air
b) Water
c) Glass
d) Diamond
Ans:
d) Diamond
Total internal reflection occurs when light travels from:
a) A rarer medium to a denser medium
b) A denser medium to a rarer medium
c) A denser medium to the same medium
d) None of the above
Ans:
b) A denser medium to a rarer medium
The working principle of a periscope is:
a) Reflection
b) Refraction
c) Diffraction
d) Polarization
Ans:
a) Reflection
An image formed by a plane mirror is always:
a) Real and inverted
b) Virtual and erect
c) Real and erect
d) Virtual and inverted
Ans:
b) Virtual and erect
A rainbow is formed due to:
a) Reflection
b) Refraction
c) Dispersion and total internal reflection
d) Only diffraction
Ans:
c) Dispersion and total internal reflection
4. Electricity & Magnetism (61-75)
Which of the following is the SI unit of electric current?
a) Volt
b) Ampere
c) Coulomb
d) Ohm
Ans:
b) Ampere
The resistance of a conductor depends on:
a) Length of the conductor
b) Cross-sectional area
c) Material of the conductor
d) All of the above
Ans:
d) All of the above
The device used to measure electric current is called:
a) Voltmeter
b) Ammeter
c) Galvanometer
d) Multimeter
Ans:
b) Ammeter
Ohm’s Law states that:
a) V = IR
b) V = I/R
c) I = VR
d) P = IV
Ans:
a) V = IR
Which of the following materials is a good conductor of electricity?
a) Rubber
b) Glass
c) Copper
d) Plastic
Ans:
c) Copper
The resistance of an ideal conductor is:
a) Zero
b) Infinity
c) One
d) None of the above
Ans:
a) Zero
The instrument used to detect electric current is:
a) Voltmeter
b) Galvanometer
c) Ammeter
d) Transformer
Ans:
b) Galvanometer
Electric power is measured in:
a) Joule
b) Watt
c) Newton
d) Ampere
Ans:
b) Watt
A transformer works on the principle of:
a) Ohm’s Law
b) Electromagnetic Induction
c) Newton’s Third Law
d) Pascal’s Law
Ans:
b) Electromagnetic Induction
In an electric circuit, a fuse is used to:
a) Increase the current
b) Reduce voltage
c) Prevent excessive current
d) Store charge
Ans:
c) Prevent excessive current
Which type of circuit has only one path for current flow?
a) Parallel circuit
b) Series circuit
c) Open circuit
d) None of the above
Ans:
b) Series circuit
If the resistance of a circuit is doubled, the current will:
a) Increase
b) Decrease
c) Remain the same
d) Become zero
Ans:
b) Decrease
Magnetic field lines always emerge from:
a) North pole to south pole
b) South pole to north pole
c) Random directions
d) None of the above
Ans:
a) North pole to south pole
Which of the following devices works on the principle of electromagnetic induction?
a) Transformer
b) Generator
c) Induction coil
d) All of the above
Ans:
d) All of the above
The unit of magnetic flux is:
a) Weber
b) Tesla
c) Henry
d) Gauss
Ans:
a) Weber
5. Modern Physics (76-80)
Who discovered the photoelectric effect?
a) Isaac Newton
b) Albert Einstein
c) J.J. Thomson
d) Nikola Tesla
Ans:
b) Albert Einstein
Which particle is responsible for the negative charge of an atom?
a) Proton
b) Neutron
c) Electron
d) Positron
Ans:
c) Electron
Which nuclear reaction is used in atomic bombs?
a) Nuclear fusion
b) Nuclear fission
c) Beta decay
d) None of the above
Ans:
b) Nuclear fission
What is the SI unit of radioactivity?
a) Becquerel
b) Curie
c) Tesla
d) Ohm
Ans:
a) Becquerel
Which radiation has the highest energy?
a) Alpha rays
b) Beta rays
c) Gamma rays
d) X-rays
Ans:
c) Gamma rays
Here are questions 81 to 100 on General Science - Physics (MCQs), continuing from where we left off.
5. Modern Physics (continued) (81-90)
Who discovered the neutron?
a) J.J. Thomson
b) James Chadwick
c) Ernest Rutherford
d) Niels Bohr
Ans:
b) James Chadwick
What is the charge of a neutron?
a) Positive
b) Negative
c) Neutral
d) Variable
Ans:
c) Neutral
Which subatomic particle was discovered first?
a) Electron
b) Proton
c) Neutron
d) Positron
Ans:
a) Electron
The phenomenon of emission of electrons from a metal surface when light falls on it is called:
a) Thermionic emission
b) Photoelectric effect
c) Compton effect
d) Pair production
Ans:
b) Photoelectric effect
Which scientist proposed the uncertainty principle?
a) Albert Einstein
b) Werner Heisenberg
c) Max Planck
d) Erwin Schrödinger
Ans:
b) Werner Heisenberg
Which of the following is NOT a fundamental force of nature?
a) Gravitational force
b) Electromagnetic force
c) Nuclear force
d) Frictional force
Ans:
d) Frictional force
Which particle is responsible for holding the nucleus together?
a) Proton
b) Electron
c) Neutron
d) Gluon
Ans:
d) Gluon
Who proposed the quantum theory of radiation?
a) Max Planck
b) Albert Einstein
c) Niels Bohr
d) Erwin Schrödinger
Ans:
a) Max Planck
The energy of a photon is given by:
a) E = mc²
b) E = hf
c) F = ma
d) E = mv²
Ans:
b) E = hf
Which type of radiation is used in cancer treatment?
a) Alpha rays
b) Beta rays
c) Gamma rays
d) X-rays
Ans:
c) Gamma rays
6. Thermodynamics & Heat (91-100)
Which of the following is a thermodynamic process in which no heat is exchanged?
a) Isothermal process
b) Adiabatic process
c) Isochoric process
d) Isobaric process
Ans:
b) Adiabatic process
What is the SI unit of heat energy?
a) Calorie
b) Joule
c) Kelvin
d) Watt
Ans:
b) Joule
The first law of thermodynamics is based on the principle of:
a) Conservation of mass
b) Conservation of energy
c) Conservation of momentum
d) Conservation of charge
Ans:
b) Conservation of energy
Absolute zero is the temperature at which:
a) Water freezes
b) Molecular motion stops
c) All gases liquefy
d) None of the above
Ans:
b) Molecular motion stops
Which mode of heat transfer does not require a medium?
a) Conduction
b) Convection
c) Radiation
d) All of the above
Ans:
c) Radiation
The efficiency of a heat engine is given by:
a) Work done / Heat absorbed
b) Work done × Heat absorbed
c) Heat absorbed / Work done
d) None of the above
Ans:
a) Work done / Heat absorbed
Which gas is most commonly used in refrigerators?
a) Oxygen
b) Nitrogen
c) Ammonia
d) Helium
Ans:
c) Ammonia
Which of the following has the highest specific heat capacity?
a) Iron
b) Copper
c) Water
d) Mercury
Ans:
c) Water
What is the boiling point of water in Kelvin?
a) 100 K
b) 273 K
c) 373 K
d) 473 K
Ans:
c) 373 K
Which law states that pressure and volume are inversely proportional at constant temperature?
a) Boyle’s Law
b) Charles’ Law
c) Gay-Lussac’s Law
d) Avogadro’s Law
Ans:
a) Boyle’s Law
