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. Speed of sound is maximum in which among the following?
[A] Solids
[B] liquids
[C] Gases
[D] Vaccum
Show Answer
Correct Answer: A [Solids]
Notes:
The speed of sound decreases when we go from solid to gaseous state.
2. When a tubelight breaks, a cracking sound is produced because ____?
[A] Pressure inside the lamp is less than atmospheric pressure
[B] Pressure inside the lamp is more than atmospheric pressure
[C] The lamp is filled with reactive gases
[D] The lamp is filled with mercury vapour
Show Answer
Correct Answer: A [Pressure inside the lamp is less than atmospheric pressure ]
Notes:
A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure.
3. Which among the following is true regarding Sound Waves?
[A] They are longitudinal waves and material medium is not required for their propagation
[B] They are transverse waves and material medium is required for their propagation
[C] They are longitudinal waves and material medium is required for their propagation
[D] They are transverse waves and material medium is not required for their propagation
Show Answer
Correct Answer: C [They are longitudinal waves and material medium is required for their propagation]
Notes:
The sound waves are longitudinal waves and material medium is not required for their propagation. The sound waves can travel through solid, liquid and gas.
4. Which among the following principle is used by Bats?
[A] RADAR (Radio Detective & Ranging
[B] SONAR (Sound Navigation & Ranging
[C] law of reflection
[D] law of diffraction
Show Answer
Correct Answer: B [SONAR (Sound Navigation & Ranging]
Notes:
Bats use SONAR (Sound Navigation & Ranging).Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.
5. Which among the following is true about latent heat ?
[A] It causes change in temperature as well as change in state or phase
[B] It causes change in temperature only
[C] It causes change in state or phase but not in temperature
[D] It causes change in Pressure
Show Answer
Correct Answer: C [It causes change in state or phase but not in temperature]
Notes:
The latent heat Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. It causes change in state or phase but not in temperature.
6. Which of the following causes the drop of water to be in spherical shape?
[A] Viscosity
[B] Air resistance
[C] Surface tension
[D] Temperature
Show Answer
Correct Answer: C [Surface tension]
Notes:
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. Surface tension allows insects, usually denser than water, to float and slide on a water surface. It is the reason for the water droplet’s round shape.
7. Nuclear Reactors are based on which of the following phenomenon?
[A] Magnetic confinement of Plasma
[B] Nuclear Fusion
[C] Controlled Nuclear Fission
[D] None of the above
Show Answer
Correct Answer: C [Controlled Nuclear Fission]
Notes:
Nuclear Reactors uses Controlled Nuclear Fission to generate electricity. A nuclear reactor splits the atoms of nuclear fuel (eg. uranium) to generate energy to turn water into steam to drive turbine generators. Nuclear fission is the splitting of a heavy nucleus into two lighter ones. Fission was discovered in 1938 by the German scientists Otto Hahn, Lise Meitner, and Fritz Strassmann.
8. Power of lens is measured in which of the following units?
[A] metre
[B] dioptre
[C] lumen
[D] watt
Show Answer
Correct Answer: B [ dioptre ]
Notes:
Power of lens is measured in dioptre(D). Power of lens = 1/focal length The power of a lens is its ability to bend light. The greater the power the greater the refraction of light.
9. 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.
10. What is the relationship between Kinetic and limiting friction?
[A] Kinetic friction is slightly greater than limiting friction
[B] Kinetic friction is slightly less than limiting friction
[C] Kinetic friction is equal to limiting friction
[D] No relationship
Show Answer
Correct Answer: B [Kinetic friction is slightly less than limiting friction]
Notes:
The Kinetic friction is always slightly less than the limiting friction. This is because once the motion has started, the inertia of has been overcome and irregularities of one surface have little or no time to get locked into the irregularities of the other surface.
