General Science - Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examinations.
41. An orbital velocity of a satellite does not depend on which of the following?
[A] Radius of the planet
[B] Mass of the planet
[C] Radius of orbit
[D] Mass of the satellite
Show Answer
Correct Answer: D [Mass of the satellite]
Notes:
An orbital velocity of a satellite does not depend on the mass of the satellite. It depends on the mass and radius of the planet around which it is orbiting. Also, it depends on the radius of the orbit or the height of the satellite.
42. What happens to the orbital velocity of a satellite when the radius of orbit is increased?
[A] it decreases
[B] it increases
[C] it remains same
[D] None of the above
Show Answer
Correct Answer: A [it decreases]
Notes:
The orbital velocity of a satellite decreases when the radius of orbit is increased or height of the satellite is increased.
43. Which of the following states of matter has the weakest Intermolecular forces?
[A] Solids
[B] Liquids
[C] Gases
[D] It is same in solids, liquids and gases
Show Answer
Correct Answer: C [Gases]
Notes:
The three states of matter varies from each other due to the following factors. (1) The different magnitudes of the interatomic and intermolecular forces. (2) The extent of random thermal motion of atoms and molecules of a substance (which depends upon temperature). The Intermolecular force is strongest in solids and weakest in gases.
44. What is the fourth state of matter called?
[A] Solid
[B] Liquid
[C] Gas
[D] Plasma
Show Answer
Correct Answer: D [Plasma]
Notes:
The fourth state of matter is called as Plasma. In Plasma, the medium is in the form of positive and negative ions. Plasma occurs in the atmosphere of stars (including the sun) and in discharge tubes.
45. What is the internal restoring force acting per unit area of cross section of the deformed body called?
[A] Strain
[B] Stress
[C] Pressure
[D] Surface Tension
Show Answer
Correct Answer: B [Stress]
Notes:
Stress is the internal restoring force acting per unit area of cross section of the deformed body. Stress is given by Force/Area.
46. What is the dimensional formula of Stress?
[A] M 1 L-2 T-2
[B] M 1 L-1 T-1
[C] M 1 L1 T-3
[D] M 1 L-1 T-2
Show Answer
Correct Answer: D [M 1 L-1 T-2]
Notes:
Stress is defined as external force per unit area on a body that tends to cause it to deform. The dimensional formula of Stress is M 1 L-1 T-2
47. What is Young’s Modulus?
[A] ratio of longitudinal strain to normal stress
[B] product of normal stress of longitudinal strain
[C] ratio of normal stress to longitudinal strain
[D] ratio of normal stress to lateral strain
Show Answer
Correct Answer: C [ratio of normal stress to longitudinal strain]
Notes:
Young’s Modulus is defined as the ratio of normal stress to longitudinal strain within limit of proportionality. Y = normal stress/longitudinal strain
48. 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.
49. What is the device used to measure the flow speed of incompressible called as?
[A] Torri-meter
[B] Bernoulli-meter
[C] Hydro-meter
[D] Venturi-meter
Show Answer
Correct Answer: D [Venturi-meter]
Notes:
The Venturi-meter is a device to measure the flow speed of incompressible fluid. It consists of a tube with a broad diameter and a small constriction at the middle.
50. What happens to a body when its density is equal to the density of the fluid?
[A] it floats
[B] it sinks
[C] it remains suspended
[D] None of the above
Show Answer
Correct Answer: C [it remains suspended]
Notes:
If the buoyant force equals the object’s weight, the object will remain suspended at that depth. If the buoyant force is greater than the object’s weight, the object will rise to the surface and float. If the buoyant force is less than the object’s weight, the object will sink. The buoyant force is always present whether the object floats, sinks, or is suspended in a fluid.
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