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. The value of acceleration due to gravity is __________?
[A] Minimum at equator and maximum at poles
[B] maximum at equator and minimum at poles
[C] equal at poles and equator
[D] None of the above
Show Answer
Correct Answer: A [Minimum at equator and maximum at poles]
Notes:
The value of acceleration due to gravity is maximum at equator. This is because the distance from the center is minimum at the equator.
2. Which among the following works while we wipe with a towel.?
[A] evaporation
[B] osmosis
[C] capillary action
[D] surface tension
Show Answer
Correct Answer: C [capillary action]
Notes:
Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The capillary action is among the following works while we wipe with a towel.
3. Which among the following provides the centripetal force to an electron circulating around the nucleus?
[A] electrostatic forces of repulsion
[B] electrostatic force of attraction
[C] speed of the electron
[D] nuclear charge
Show Answer
Correct Answer: B [electrostatic force of attraction]
Notes:
The correct answer is “electrostatic force of attraction.” In an atom, electrons are negatively charged and are attracted to the positively charged nucleus due to Coulomb’s law. This attraction provides the necessary centripetal force to keep the electron in a stable orbit around the nucleus. The balance between this electrostatic force and the electron’s inertia allows for stable atomic structures.
4. Which among the following correctly represents a Parsec?
[A] 0.326 Light Years
[B] 3.261 Light Years
[C] 32.61 Light Years
[D] 3.026 Light Years
Show Answer
Correct Answer: B [3.261 Light Years]
Notes:
One parsec is approximately equal to 31 trillion kilometres (19 trillion miles), or 210,000 astronomical units, and equates to about 3.3 light-years.
5. If the time taken in an echo is 5 seconds, which among the following will be the approximate distance of the object from source of sound? (assume normal room temperature at 20°C)
[A] 1715 meters
[B] 1256 meters
[C] 857 meters
[D] 554 meters
Show Answer
Correct Answer: C [ 857 meters]
Notes:To calculate the distance of the object from the source of sound based on the time taken for the echo, we can use the formula for distance traveled by sound:
Distance = (Speed of Sound × Time) / 2
The speed of sound in air at normal room temperature (20°C) is approximately 343 meters per second (m/s).
Given that the time taken in the echo is 5 seconds, we can plug the values into the formula:
Distance = (343 m/s × 5 s) / 2 Distance = 1715 meters / 2 Distance ≈ 857.5 meters
So, the approximate distance of the object from the source of sound is approximately 857.5 meters.
6. Large Underground Xenon experiment (LUX) is being carried out in which country?
[A] U.S.A
[B] Russia
[C] China
[D] Japan
Show Answer
Correct Answer: A [ U.S.A]
Notes:
Large Underground Xenon experiment (LUX) is located 1,510 m underground at the Sanford Underground Laboratory in Lead city, South Dakota, United States.
7. What is the value of Triple point of water?
[A] 273.16 K
[B] 273.16° C
[C] 0° C
[D] -273.16 K
Show Answer
Correct Answer: A [ 273.16 K ]
Notes:
Triple point of water is the temperature at which ice, water and water vapours coexist. The value of Triple point of water is 273.16 K Kelvin is the S.I unit of Temperature represented by symbol K.
8. What is the relation between Time period and Frequency in case of uniform circular motion?
[A] reciprocal to each other
[B] equal to each other
[C] no relation between them
[D] Time period is one half of the Frequency
Show Answer
Correct Answer: A [reciprocal to each other]
Notes:
Time period and Frequency are reciprocal to each other in case of uniform circular motion. Time period = 1 /Frequency Time Period is the time taken by the object to complete one revolution. Frequency is the number of revolutions completed by the object in unit time.
9. The forces acting at a point are called as:
[A] Collinear forces
[B] Coplanar forces
[C] Concurrent forces
[D] Unit forces
Show Answer
Correct Answer: C [Concurrent forces]
Notes:
The forces which are acting at a point are called as concurrent forces. Note: When concurrent forces in equilibrium act on a body, the state of the body shall remain unchanged i.e. if the body is at rest, it will continue to be at rest. Similarly, a body will continue to move uniformly along the same straight line, if concurrent forces in equilibrium are applied on the body.
10. The work done in moving a body over a smooth inclined plane does not depend on which of the following?
[A] mass of the body
[B] height of the inclined plane
[C] slope of the inclined plane
[D] All of the above
Show Answer
Correct Answer: C [slope of the inclined plane]
Notes:
The work done in moving a body over a smooth inclined plane does not depend on the slope of the inclined plane. W = mgh in case of smooth inclined plane, where m = mass of the body, g = acceleration due to gravity and h = height of the inclined plane.
