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.
11. What is the maximum height that can be attained by a projectile?
[A] equal to its maximum range
[B] one half of its maximum range
[C] one-fourth of its maximum range
[D] twice of its maximum range
Show Answer
Correct Answer: C [one-fourth of its maximum range]
Notes:
The maximum height that can be attained by a projectile is equal to one-fourth of its maximum range.
12. 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.
13. The distance of Neptune and Saturn from sun are nearly 1013 and 1012 meters respectively. Assuming that they move in circular orbits, what will be the ratio of their periodic times?
[A] 40
[B] 10√10
[C] 20√20
[D] 30√30
Show Answer
Correct Answer: B [10√10]
Notes:
By using Kepler’s third law, Tneptune/Tsaturn = (Rneptune/Rsaturn)3/2
14. What do we call the strain produced in a body when the deforming force produces a change in its shape without changing its volume?
[A] Linear Strain
[B] Volumetric Strain
[C] Shearing strain
[D] Thermal Strain
Show Answer
Correct Answer: C [Shearing strain]
Notes:
When the deforming force produces a change in the shape of the body without changing its volume, the strain produced is called shearing strain.
15. Which of the following is equal to the upthrust of the body?
[A] mass of body
[B] weight of liquid
[C] weight of liquid displaced
[D] density of liquid
Show Answer
Correct Answer: C [weight of liquid displaced]
Notes:
Archimedes Principle: when a body is immersed partially or completely in a liquid, it experiences an upthrust, which is equal to the weight of the liquid displaced by the body.
16. What is the relationship between excess pressure and the radius of the bubble?
[A] are equal in value
[B] inversely proportional to each other
[C] directly proportional to each other
[D] no relationship
Show Answer
Correct Answer: B [inversely proportional to each other]
Notes:
Excess pressure is inversely proportional to the radius of bubble (or drop). It means that the pressure inside a smaller bubble is higher than inside a larger bubble.
17. What do we call the potential energy of surface molecules per unit area of the surface?
[A] Surface energy
[B] Surface Tension
[C] Reynolds number
[D] Potential constant
Show Answer
Correct Answer: A [Surface energy]
Notes:
The potential energy of surface molecules per unit area of the surface is called as surface energy. Some work is required to be done, in bringing a molecule from the interior of the liquid to the free surface, against the intermolecular force of attraction. This work which is stored as potential energy of the molecule on the surface.
18. What is the density of water at 4°?
[A] 1.0
[B] 1.0 × 102 kg m–3
[C] 1.0 × 103 kg m–3
[D] 10 kg m–3
Show Answer
Correct Answer: C [ 1.0 × 103 kg m–3 ]
Notes:
The density of water at 4°C (277 K) is 1.0 × 103 kg m–3. The relative density of a substance is the ratio of its density to the density of water at 4° C.
19. 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
Show Answer
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.
20. Which of the following eaves will be produced on bombarding a metal target by high energy electrons?
[A] Gamma rays
[B] X rays
[C] Infra red
[D] Microwaves
Show Answer
Correct Answer: B [X rays]
Notes:
One common way to generate X-rays is to bombard a metal target by high energy electrons. X-rays covers wavelengths from about 10–8 m (10 nm) down to 10–13 m (10–4 nm).
