General Science - 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. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
21. Two satellites, A having mass of 500 kgs and B having mass of 1200 kgs, are launched from earth. Which of these will have a greater orbital velocity if the radius of orbit is same for both?
[A] Satellite A
[B] Satellite B
[C] Both satellites will have the same orbital velocity
[D] Cant be determined
Show Answer
Correct Answer: C [Both satellites will have the same orbital velocity]
Notes:
Both satellites will have the same orbital velocity as the orbital velocity of a satellite is independent of mass of satellite.
22. Which of these represent the Angular momentum of a satellite?
[A] mvr
[B] ma
[C] mr
[D] mvh
Show Answer
Correct Answer: A [mvr]
Notes:
Angular momentum of satellite is given by mvr. Angular momentum of satellite depend on both the mass of orbiting and central body as well as the radius of orbit.
23. What is the unit of Stress?
[A] N/m
[B] Kg/m
[C] Nm
[D] It has no units
Show Answer
Correct Answer: A [N/m]
Notes:
If an external force F is applied on the area A of a body then, Stress is given by Force/Area Units of Stress: S.I unit: N / m C.g.s unit: dyne / cm
24. Which of the following is the correct equivalent of 1 atmosphere?
[A] 1 atmosphere = 1.013 × 105Pa
[B] 1 atmosphere = 1.013 × 104Pa
[C] 1 atmosphere = 1.013 × 103Pa
[D] 1 atmosphere = 1.013 × 102Pa
Show Answer
Correct Answer: A [1 atmosphere = 1.013 × 105Pa]
Notes:
A common unit of pressure is the atmosphere (atm), i.e. the pressure exerted by the atmosphere at sea level (1 atm = 1.013 × 105Pa).
25. What happens to a body when its density is greater than the density of the fluid?
[A] it floats
[B] it sinks
[C] it stays at rest
[D] None of the above
Show Answer
Correct Answer: B [it sinks]
Notes:
The body sinks in the fluid in case its density is greater than the density of the fluid. For example, an iron nail has greater density than water, therefore it sinks in water.
26. What is the phase of a vibrating particle at t = 0 known as?
[A] epoch
[B] eon
[C] path difference
[D] period
Show Answer
Correct Answer: A [epoch]
Notes:
Initial phase or epoch is the phase of a vibrating particle at t = 0. When t = 0; Phase is the angle of epoch.
27. In which of the following positions is the potential energy minimum in S.H.M?
[A] Extreme position
[B] Mean position
[C] can be at extreme or mean position
[D] None of the above
Show Answer
Correct Answer: B [Mean position]
Notes:
Potential energy maximum and equal to total energy at extreme positions. Potential energy is minimum at mean position.
28. What will be the spring constant of each part if the spring of force constant k is divided in to n equal parts?
Show Answer
Correct Answer: C [nk]
Notes:
If the spring of force constant k is divided in to n equal parts then spring constant of each part will become nk.
29. Which of these means opposite phase of particles?
[A] phase difference between the particle is an odd multiple of π
[B] if the path difference is an odd multiple of (λ / 2)
[C] if the time interval is an odd multiple of T/2
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Opposite Phase means: phase difference between the particle is an odd multiple of π or if the path difference is an odd multiple of (λ / 2) or if the time interval is an odd multiple of T/2
30. Which of the following produces Electromagnetic waves?
[A] charges at rest
[B] charges in uniform motion
[C] accelerated charges
[D] All of the above
Show Answer
Correct Answer: C [accelerated charges]
Notes:
Neither stationary charges nor charges in uniform motion (steady currents) can be sources of electromagnetic waves. The former produces only electrostatic fields, while the latter produces magnetic fields that, however, do not vary with time. As per Maxwell’s theory, accelerated charges radiate electromagnetic waves.
