Physics is a very important subject because it helps us understand how things work in the world around us. It is also the base for many topics in engineering and technology. Some key areas in physics like Magnetic Fields, Electromagnetism, Heat, Thermodynamics, and Fluid Mechanics, are often seen in exams and tests. One of the best ways to review these topics is by practicing Multiple Choice Questions (MCQs). The 40 questions in this set are made to match what you’ve learned in class. Each question is written in a clear way to help you test both your knowledge and how well you can apply what you’ve learned. The correct answer is given right after each question, so you can check yourself quickly.
1. A freely suspended bar magnet always comes to rest in a particular direction, which gives evidence about the Earth’s magnetic field. What is this natural alignment of the magnet?
a) East–West direction
b) North–South direction
c) Vertical to Earth’s surface
d) Random orientation each time
Answer: b) North–South direction
2. Which of the following is an application of Archimedes’ principle in daily life?
a) Working of hydraulic brakes
b) Rise of hot air balloons
c) Lift in airplane wings
d) Heat transfer from Sun
Answer: b) Rise of hot air balloons
3. Bernoulli’s theorem explains that when the velocity of a fluid becomes higher, its:
a) Pressure decreases
b) Pressure increases
c) Density decreases
d) Volume increases
Answer: a) Pressure decreases
4. The magnetic field around a straight conductor depends on two main factors. Which combination is correct?
a) Increases with distance and decreases with current
b) Increases with current and decreases with distance
c) Independent of current but depends on shape
d) Remains constant regardless of current or distance
Answer: b) Increases with current and decreases with distance
5. The property of liquid surface to contract and acquire minimum surface area is called:
a) Elasticity
b) Capillarity
c) Surface tension
d) Viscosity
Answer: c) Surface tension
6. The apparent loss of weight of a body in a fluid is equal to:
a) Its actual weight
b) The weight of the liquid displaced
c) Its density multiplied by volume
d) Its volume only
Answer: b) The weight of the liquid displaced
7. Bernoulli’s principle relates which of the following quantities in a streamline flow?
a) Pressure, velocity, and density
b) Pressure, temperature, and volume
c) Density, viscosity, and temperature
d) Force, work, and time
Answer: a) Pressure, velocity, and density
8. The rise or fall of liquid in a capillary tube is due to:
a) Surface tension
b) Viscosity
c) Pressure difference
d) Density
Answer: a) Surface tension
9. The opposite force that a fluid exerts on an object when it moves is known as:
a) Surface tension
b) Buoyancy
c) Viscous drag
d) Elasticity
Answer: c) Viscous drag
10. When the velocity of a fluid increases beyond a certain limit, the streamline flow breaks and becomes:
a) Laminar flow
b) Turbulent flow
c) Viscous flow
d) Stationary flow
Answer: b) Turbulent flow
11. Heat is transferred by different modes. Which of the following transfers heat by direct molecular contact without bulk movement of particles?
a) Radiation
b) Conduction
c) Convection
d) Expansion
Answer: b) Conduction
12. In which of the following processes does heat travel through a medium due to the actual movement of molecules from one place to another?
a) Conduction
b) Convection
c) Radiation
d) Absorption
Answer: b) Convection
13. Which method of heat transfer does not require any medium and can occur even in a vacuum?
a) Convection
b) Radiation
c) Conduction
d) Diffusion
Answer: b) Radiation
14. A body sinks completely in a fluid if:
a) Density of body < density of fluid
b) Density of body > density of fluid
c) Weight of fluid > weight of body
d) Buoyant force = weight of body
Answer: b) Density of body IS GREATER density of fluid
15. The unit of heat in the SI system is:
a) Calorie
b) Joule
c) Erg
d) Watt
Answer: b) Joule
16. The amount of heat required to raise the temperature of 1 kilogram of a substance by 1°C is called:
a) Latent heat
b) Specific heat capacity
c) Thermal conductivity
d) Heat flux
Answer: b) Specific heat capacity
17. The heat required to change 1 kilogram of a substance from solid to liquid state without changing temperature is known as:
a) Latent heat of vaporization
b) Latent heat of fusion
c) Specific heat
d) Heat capacity
Answer: b) Latent heat of fusion
18. The transfer of heat from the Sun to Earth takes place by:
a) Conduction through air
b) Convection currents in the atmosphere
c) Radiation across space
d) Thermal conduction through the ozone layer
Answer: c) Radiation across space
19. An instrument made for determining the pressure exerted by a fluid is known as:
a) Hydrometer
b) Manometer
c) Thermometer
d) Voltmeter
Answer: b) Manometer
20. The upward lift of an airplane wing is explained using which principle?
a) Archimedes’ principle
b) Pascal’s law
c) Bernoulli’s theorem
d) Law of inertia
Answer: c) Bernoulli’s theorem
21. The upward force experienced by a body immersed in a fluid is called:
a) Viscosity
b) Buoyant force
c) Drag force
d) Surface tension
Answer: b) Buoyant force
22. Archimedes’ principle states that:
a) Every liquid exerts equal pressure in all directions
b) The loss of weight of a body immersed in a liquid is equal to the weight of liquid displaced
c) Pressure in a fluid increases
Answer: b) The loss of weight of a body immersed in a liquid is equal to the weight of liquid displaced
23. A body floats in a liquid if:
a) Density is higher than the liquid density
b) Density is less than or equal to the liquid density
c) It is irregular in shape
d) It’s regular in shape
Answer: b) Density is less or equal to liquid density
24. Pascal’s law states that:
a) Pressure at a point inside a liquid is independent of direction
b) Pressure in a confined liquid is transmitted equally in all directions
c) Pressure in a liquid increases with depth
d) Pressure decreases with height above ground
Answer: b) Pressure in a confined liquid is transmitted equally in all directions
25. Which device works on the principle of Pascal’s law?
a) Hydraulic lift
b) Electric motor
c) Dynamo
d) Barometer
Answer: a) Hydraulic lift