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. Which among the following is measured using a Vernier Caliper?
[A] Dimensions
[B] Time
[C] Sound
[D] Temperature
Show Answer
Correct Answer: A [Dimensions]
Notes:
The Vernier caliper has a main scale and a sliding vernier scale which can measure nearest to 0.02 mm. It can be used to measure internal and the external dimensions of an object by using the smaller jaws at the top and the main jaws respectively. By using stems depth can be measured.
2. Knot is a unit of _________?
[A] Speed
[B] Distance
[C] Deapth
[D] Accelration
Show Answer
Correct Answer: A [Speed]
Notes:
Knot is a unit of speed equal to one nautical mile per hour. 1 knot is equivalent to 1.852 km/h. “kn” is the ISO standard symbol of knot. It is used in the field of meteorology, maritime and air navigation.
3. 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.
4. When light from some sources enters to the earth’s atmosphere, it gets scattered. Which among the following is a reason behind scattering?
[A] Various wavelengths of light
[B] dust, smoke and gas molecules
[C] atmospheric pressure
[D] None of the above
Show Answer
Correct Answer: B [dust, smoke and gas molecules]
Notes:
Scattering of light is the phenomenon in which light rays get deviated from its straight path on striking an obstacle.The scattering of light can be of many reason. Some of them are dust, smoke and gas molecules.
5. On which of the following the jet Engine works?
[A] Conservation of energy
[B] Conservation of Linear Momentum
[C] Conservation of Mass
[D] Conservation of Angular momentum
Show Answer
Correct Answer: B [Conservation of Linear Momentum]
Notes:Conservation of Linear Momentum law says that if no external force acts on a system, then its total linear momentum remains conserved. In equation form, Momentum=mass*velocity. To increase the momentum of an object, we need to either increase its mass or velocity or both.
- Rockets work on law of conservation of momentum. As momentum in one direction is given to the rocket’s exhaust gases, momentum in the other direction is given to the rocket itself.
6. Fermi-Kurie plot is used for the study of which of the following?
[A] Alpha Decay
[B] Beta Decay
[C] Internal Conversion
[D] Cluster Decay
Show Answer
Correct Answer: B [Beta Decay]
Notes:
Fermi–Kurie plot is a graph developed by Franz N. D. Kurie and is used in studying beta decay. In this graph square root of the number of beta particles whose energy lie within a specific range, divided by the Fermi function, is plotted against beta-particle energy.
7. Which among the following strictly works on the principle of dipole movement of the water molecules?
[A] Refrigerator
[B] Microwave Oven
[C] Air Conditioner
[D] Electric Geyser
Show Answer
Correct Answer: B [Microwave Oven]
Notes:
Microwave Oven strictly works on the principle of dipole movement of water molecule. A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.
8. We can hear a whooshing sound when we hold a spiral conch shell near our ears. What is the most likely reason behind this?
[A] The sound we hear is echoing of our blood rushing through the blood vessels of our ear
[B] The sound is generated by air flowing through the shell – in and out
[C] The ambient noise around us resonates inside the shell
[D] None of the reasons mentioned in statements A, B or C is correct
Show Answer
Correct Answer: C [ The ambient noise around us resonates inside the shell]
Notes:
The most likely explanation for the wave-like noise is ambient noise from around us. The seashell that we hold just slightly above our ear captures this noise, which resonates inside the shell.
9. When you throw a ball with an angle to the horizontal (projectile); the ball has __:
[A] Uniform velocity in horizontal direction but uniform acceleration in vertical direction
[B] Uniform acceleration in horizontal direction but uniform velocity in vertical direction
[C] Uniform acceleration in both horizontal and vertical directions
[D] Uniform velocity in both horizontal and vertical directions
Show Answer
Correct Answer: A [ Uniform velocity in horizontal direction but uniform acceleration in vertical direction]
Notes:
The motion of a projectile is two dimensional motion consisting of (i) horizontal motion and (ii) vertical motion. Hence, at any instant, the velocity of a projectile has two components (i) horizontal component and (ii) vertical component. The horizontal component remains unchanged throughout the flight as there is no acceleration in horizontal direction. The vertical component is continuously affected by the force of gravity. Thus, the horizontal motion is uniform motion but the vertical motion is uniformly accelerated motion.)
10. Which of the following is correct about Kinetic energy during the projectile motion?
[A] it is minimum at the point of projection
[B] it is minimum at the highest point
[C] it is maximum at the highest point
[D] it is minimum at the point of reaching the ground
Show Answer
Correct Answer: B [it is minimum at the highest point]
Notes:
The Kinetic energy of an object is maximum at the point of projection or at the point of reaching the ground. It is minimum at the highest point.
