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. Ohm is a unit of measuring _________?
[A] Resistance
[B] Voltage
[C] Current
[D] None of the above
Show Answer
Correct Answer: A [Resistance]
Notes:
The ohm is the SI unit of electrical resistance. Electrical resistance of an object is the measure of its obstruction to the flow of electric current. It mainly depends on the material it is made of, cross sectional area of a conductor, length and temperature. The resistance of a conductor of unit cross-sectional area and unit length is known as Resistivity. The unit of resistivity is ohm-metre.
2. Which among the following has highest velocity ?
[A] Hurricane
[B] Tornado
[C] Typhoon
[D] Cyclone
Show Answer
Correct Answer: B [Tornado]
Notes:
Tornadoes has the highest velocity and are more devastating compared to other types of cyclones. They generally occur in the pacific ocean.
3. Steam at 100 degree centigrade causes more severe burns. Which of the following phenomena will you use to explain this?
[A] Specific heat
[B] Latent heat
[C] Fusion
[D] Fission
Show Answer
Correct Answer: B [Latent heat]
Notes:
Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. So steam at 100 degree centigrade causes more severe burns.
4. A person weighing 80 Kg. is standing on an accurate scale in an elevator. The elevator is slowing down while moving downwards. In this case the scale will read__?
[A] 80 Kg.
[B] Less than 80 Kg
[C] More than 80 Kg
[D] Either less or more than 80 Kg
Show Answer
Correct Answer: C [More than 80 Kg]
Notes:
When the elevator is slowing down while moving downwards, that means there is an acceleration upwards. The gravitational force must be lesser than the normal force. Thus, during slowing down while moving downwards, the normal force on the feet of a passenger is greater than her weight. In this case the scale will read more than 80 kg.
5. 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.
6. What is the S.I unit of Coefficient of Mutual inductance?
[A] weber
[B] candela
[C] henry
[D] lambert
Show Answer
Correct Answer: C [ henry ]
Notes:
The unit of Coefficient of Mutual inductance is henry lambert is the S.I unit of Luminance weber is the S.I unit of Magnetic Flux candela is the S.I unit of Luminous Intensity
7. Which of the these physical quantities is a vector quantity?
[A] Temperature
[B] Speed
[C] Gravitational Intensity
[D] Work
Show Answer
Correct Answer: C [Gravitational Intensity]
Notes:
The physical quantities which have both magnitude and direction are called as Vector quantities. Some examples of Vector quantities: Acceleration, Velocity, Torque, Displacement, Gravitational Intensity, Force.
8. A projectile will achieve maximum horizontal range at which angle?
[A] 90°
[B] 60°
[C] 45°
[D] 30°
Show Answer
Correct Answer: C [45°]
Notes:
A projectile will achieve maximum horizontal range when it is projected at an angle of 45°. This concept of maximum horizontal range is used by athletes in long jump, javelin throw, cricket ball throw etc
9. Which of these is the cause of Friction?
[A] Roughness of surfaces in contact
[B] Force of adhesion between the molecules of the surfaces in contact
[C] Both a and b
[D] None of the above
Show Answer
Correct Answer: C [Both a and b]
Notes:
Friction is the force that opposes the relative motion between the two surfaces of objects in contact. Friction is caused due to: 1. Roughness of surfaces in contact 2. Force of adhesion between the molecules of the surfaces in contact
10. Which of the following is correct about the coefficient of limiting friction between any two surfaces in contact?
[A] it is equal to twice the tangent of angle of friction
[B] it is equal to twice the sine of angle of friction
[C] it is equal to the tangent of angle of friction
[D] it is equal to the sine of angle of friction
Show Answer
Correct Answer: C [it is equal to the tangent of angle of friction]
Notes:
The coefficient of limiting friction between any two surfaces in contact is equal to the tangent of angle of friction between them. u = tan Q where u = coefficient of limiting friction and Q = angle of friction
