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. Fermi-Kurie plot is used for the study of which of the following?
[A] Alpha Decay
[B] Beta Decay
[C] Internal Conversion
[D] Cluster Decay
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Correct Answer: B [Beta Decay]
Notes:
Fermi–Kurie plot is a graph developed by Franz N. D. Kurie and is used in studying beta decay. In this graph square root of the number of beta particles whose energy lie within a specific range, divided by the Fermi function, is plotted against beta-particle energy.
2. Which of the following pairs represent two scalar quantities?
[A] Mass, Acceleration
[B] Temperature, Torque
[C] Distance, Speed
[D] Gravitational Intensity, Work
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Correct Answer: C [Distance, Speed]
Notes:
The physical quantities which have only magnitude and no direction are called as Scalar quantities. Some examples of Scalar quantities: Work, Mass, Temperature, Distance, Speed.
3. A projectile will achieve maximum horizontal range at which angle?
[A] 90°
[B] 60°
[C] 45°
[D] 30°
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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
4. The centripetal force and centrifugal force are ______:
[A] equal in magnitude and have same direction
[B] unequal in magnitude and have same direction
[C] equal in magnitude and have opposite direction
[D] unequal in magnitude and have opposite direction
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Correct Answer: C [equal in magnitude and have opposite direction]
Notes:
The centripetal force and centrifugal force are equal in magnitude and have opposite direction. Centrifugal force can be regarded as the reaction of centripetal force.
5. The capacity of a body to do work is known as:
[A] Energy
[B] Power
[C] Momentum
[D] Strength
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Correct Answer: A [Energy]
Notes:
Energy of a body is the capacity or the ability of a body to do the work. Energy is a scalar quantity having magnitude but no direction. Its unit is same as that of Work S.I. unit: joule In c.g.s system, unit is erg.
6. What is the body called which does not have any tendency to recover its original configuration, on the removal of deforming force?
[A] Perfectly plastic
[B] Perfectly elastic
[C] Perfectly ductile
[D] None of the above
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Correct Answer: A [Perfectly plastic]
Notes:
Perfectly plastic: If the body does not have any tendency to recover its original configuration, on the removal of deforming force, it is said to be perfectly plastic. Paraffin wax, wet clay can be the closest example of the perfectly plastic body.
7. What is the internal restoring force acting per unit area of cross section of the deformed body called?
[A] Strain
[B] Stress
[C] Pressure
[D] Surface Tension
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Correct Answer: B [Stress]
Notes:
Stress is the internal restoring force acting per unit area of cross section of the deformed body. Stress is given by Force/Area.
8. What is Young’s Modulus?
[A] ratio of longitudinal strain to normal stress
[B] product of normal stress of longitudinal strain
[C] ratio of normal stress to longitudinal strain
[D] ratio of normal stress to lateral strain
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Correct Answer: C [ratio of normal stress to longitudinal strain]
Notes:
Young’s Modulus is defined as the ratio of normal stress to longitudinal strain within limit of proportionality. Y = normal stress/longitudinal strain
9. What is the order of distance for Vander Wall forces to be active?
[A] 10–6 metre
[B] 10–7 metre
[C] 10–8 metre
[D] 10–9 metre
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Correct Answer: D [10–9 metre]
Notes:
The forces between the molecules because of the electrostatic interaction between the charges of the molecules are called intermolecular forces. These forces are also called Vander Waal forces. They are quite weak as compared to inter-atomic forces. These forces are also electrical in nature. They are active if the separation between two molecules is of the order of molecular size i.e. 10–9 metre.
10. Who was the first to state the principle of floatation?
[A] Isaac Newton
[B] Archimedes
[C] Aristotle
[D] Galileo Galilei
Show Answer
Correct Answer: B [Archimedes]
Notes:
Archimedes, the Ancient Greek scientist was the first to state the principle of floatation. Archimedes principle states that when a body is immersed partly or wholly in a liquid, there is an apparent loss in the weight of the body which is equal to the weight of liquid displaced by the body.
