Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
11. The energy by virtue of its position is known as:
[A] Kinetic energy
[B] Potential energy
[C] Internal energy
[D] Heat energy
Show Answer
Correct Answer: B [Potential energy]
Notes:
The energy by virtue of its position is known as Potential energy. The energy by virtue of its motion is known as Kinetic energy.
12. The value of acceleration due to gravity is minimum on which of these planets?
[A] Mars
[B] Jupiter
[C] Mercury
[D] Neptune
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Correct Answer: C [Mercury]
Notes:
The value of acceleration due to gravity is minimum on planet Mercury and maximum on planet Jupiter.
13. By how much times the orbital speed of a satellite needs to be increased to make it escape the gravitational field?
[A] √3 times
[B] 4 times
[C] 2 times
[D] √2 times
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Correct Answer: D [√2 times]
Notes:
It means that if the speed of a satellite orbiting close to the earth is made √2 times (or increased by 41%) then it will escape from the gravitational field.
14. Which of the following strains is produced in a body if the deforming force produces a change in the shape of the body without changing its volume?
[A] Linear
[B] Volumetric
[C] Shearing
[D] All of the above
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Correct Answer: C [Shearing]
Notes:
If the deforming force produces a change in the shape of the body without changing its volume, the strain produced in the body is called as shearing strain. Shearing strain is defined as angle in radians through which a plane perpendicular to the fixed surface of the cubical body gets turned under the effect of tangential force.
15. On which of the following factors the breaking stress depends?
[A] Area of cross-section
[B] length of the material
[C] Nature of the material
[D] None of the above
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Correct Answer: C [Nature of the material]
Notes:
Breaking force = P × A Here P is a constant of proportionality and known as breaking stress. Breaking stress is constant for a given material and does not depend upon the dimension (length or thickness) of wire.
16. Which is the effect of increase in impurities on the surface tension of the liquid?
[A] It increases
[B] It decreases
[C] It may increase or decrease
[D] No change
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Correct Answer: C [It may increase or decrease]
Notes:
The presence of impurities considerably affect the force of surface tension, depending upon the degree of contamination. A highly soluble substance like sodium chloride when dissolved in water, increases the surface tension of water. But the sparingly soluble substances like phenol when dissolved in water, decreases the surface tension of water.
17. Which of these is correct about Simple Harmonic Motion?
[A] Restoring force is directly proportional to the displacement from mean position
[B] Restoring force is equal to the displacement from mean position
[C] Restoring force is inversely proportional to the displacement from mean position
[D] Restoring force is half of the displacement from mean position
Show Answer
Correct Answer: A [Restoring force is directly proportional to the displacement from mean position]
Notes:
Simple harmonic motion is a special type of periodic motion, in which a particle moves to and fro repeatedly about a mean position under a restoring force which is always directed towards the mean position and whose magnitude at any instant is directly proportional to the displacement of the particle from the mean position at that instant. Restoring force Displacement of the particle from mean position.
18. What is the definition of a second’s pendulum?
[A] A pendulum that completes one full swing in a second
[B] A pendulum that swings twice in a second
[C] A pendulum that has a length of one second
[D] A pendulum that was invented by Secondus
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Correct Answer: A [A pendulum that completes one full swing in a second]
Notes:
A second’s pendulum, also known as a seconds pendulum, is defined as a pendulum whose period of oscillation is precisely two seconds, one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. It was once used to define the second of time.
19. What is the relationship between the spring constant k and the spring length in case of spring pendulum?
[A] spring constant is inversely proportional to the spring length
[B] spring constant is directly proportional to the spring length
[C] spring constant is independent of the spring length
[D] spring constant is twice the spring length
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Correct Answer: A [spring constant is inversely proportional to the spring length]
Notes:
The spring constant of a spring pendulum is inversely proportional to the spring length.
20. What kinds of waves are the ultrasonic waves in air produced by a vibrating quartz crystal?
[A] Transverse
[B] Longitudinal
[C] Transverse and longitudinal
[D] None of the above
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Correct Answer: B [Longitudinal]
Notes:
The ultrasonic waves in air produced by a vibrating quartz crystal are longitudinal waves.