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. “Svedberg Unit” is a measure of?
[A] Concentration
[B] Size
[C] Density
[D] Time
Show Answer
Correct Answer: D [Time]
Notes:
A Svedberg unit (S/ Sv) is utilized to denote sedimentation coefficients, providing specific measurement of a particle based on its sedimentation rate under acceleration. Essentially, it computes how quickly a particle settles to the bottom of a solution. In terms of the time dimension, a Svedberg unit amounts to exactly 10−13 seconds, indicating that it is essentially a measure of time.
2. You are sitting inside an open vehicle moving with uniform speed. When you throw a stone vertically upwards, the stone will fall__:
[A] Ahead of you
[B] Behind you
[C] Over you
[D] Either ahead or behind of you
Show Answer
Correct Answer: C [ Over you]
Notes:
Uniform speed means no acceleration. If there is no acceleration and the vehicle is moving with uniform speed; the stone will fall over you.
3. Which of the following units is NOT used for measuring length?
[A] Astronomical Unit
[B] Light year
[C] Par sec
[D] slug
Show Answer
Correct Answer: D [ slug ]
Notes:
Astronomical Unit, Light year and Par sec are the units used to measure very large distances whereas slug is a unit to measure heavy masses. 1 slug = 14.57 kg
4. Which of the following is true about displacement of an object?
[A] It is always equal to the distance travelled by the object
[B] It can be less than the distance travelled by the object
[C] It can be greater than the distance travelled by the object
[D] It always less than the distance travelled by the object
Show Answer
Correct Answer: B [It can be less than the distance travelled by the object]
Notes:
The displacement is the shortest distance between the initial and final position of an object in the given time. The displacement of an object is a vector quantity. It can be less than or equal to the distance but can never be greater than the distance travelled by that object
5. 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.
6. 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
Show Answer
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.
7. What do we call the minimum velocity with which a body must be projected up, so as to enable it to just overcome the gravitational pull?
[A] Orbital velocity
[B] Gravitational velocity
[C] Escape velocity
[D] None of the above
Show Answer
Correct Answer: C [Escape velocity]
Notes:
The minimum velocity with which a body must be projected up, so as to enable it to just overcome the gravitational pull, is known as Escape velocity. Ve = (2gR)1/2
8. Which of the following is incorrect about a satellite?
[A] It is a freely falling body
[B] it does not require energy for its motion in orbit
[C] it suffers an acceleration
[D] it moves with constant speed
Show Answer
Correct Answer: C [it suffers an acceleration]
Notes:
A satellite is a freely falling body. it does not require energy for its motion in orbit and its speed is constant.
9. What is the ratio of normal stress to the volumetric strain within the elastic limits is called as?
[A] Bulk Modulus
[B] Young Modulus
[C] Modulus of Rigidity
[D] None of the above
Show Answer
Correct Answer: A [Bulk Modulus]
Notes:
The ratio of normal stress to the volumetric strain within the elastic limits is called as Bulk modulus. It is denoted by K.
10. What is the property of a liquid due to which its free surface tries to have minimum surface area?
[A] Viscosity
[B] Buoyancy
[C] Surface Tension
[D] Rigidity
Show Answer
Correct Answer: C [Surface Tension]
Notes:
The property of a liquid due to which its free surface tries to have minimum surface area and behaves as if it were under tension somewhat like a stretched elastic membrane is called surface tension.
