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. What is the use of Venturimeter?
[A] to measure subdivisions of scale
[B] to measure wavelength of radio wave
[C] To measure friction
[D] to measure rate of flow of fluids
Show Answer
Correct Answer: D [to measure rate of flow of fluids]
Notes:
A Venturimeter is the device used to measure rate of flow of fluids. This device is based on the principle of Bernoulli’s Equation.
2. Which of the following is an instrument for measuring electric charge or electrical potential difference?
[A] Ammeter
[B] Voltmeter
[C] Electrometer
[D] ohmmeter
Show Answer
Correct Answer: B [Voltmeter]
Notes:
Voltmeter is an instrument for measuring electric charge or electrical potential difference. It was invented by Hans Christian Oersted.
3. A person is standing in front of a wall and makes a sound. What should be the normal minimum distance between the person and the wall , so that the person hears echo?
[A] 6 meters
[B] 13 meters
[C] 20 meters
[D] 17 meters
Show Answer
Correct Answer: D [17 meters]
Notes:
To hear an echo, the minimum distance between a wall and the source of sound is 17m. The minimum interval is 0.1 sec.
4. The X-ray crystallography mainly uses which among the following properties of electromagnetic radiation?
[A] Reflection
[B] Diffraction
[C] Interference
[D] Refraction
Show Answer
Correct Answer: B [ Diffraction]
Notes:
X-ray crystallography helps to determine the atomic and molecular structure of a crystal. The crystalline structure performs the diffraction and it causes a beam of incident X-rays to diffract into many specific directions.
5. An Electric generator is based on which of the following scientific principles?
[A] Faraday’s law of Electromagnetic Induction
[B] Super Conductivity
[C] Laws of Thermodynamics
[D] Newton’s Law of Motion
Show Answer
Correct Answer: A [Faraday’s law of Electromagnetic Induction]
Notes:
An Electric generator works on the principle of Faraday’s law of Electromagnetic Induction. An electric generator uses mechanical energy to generate electricity applying Faraday’s law of induction. It spins a coil at a constant rate in a magnetic field to induce an oscillating emf.
6. Which of the following options is a representation of non-uniform motion?
[A] Equal displacements in unequal intervals of time
[B] Unequal displacements in unequal intervals of time
[C] Equal displacements in equal intervals of time
[D] Unequal displacements in equal intervals of time
Show Answer
Correct Answer: A [Equal displacements in unequal intervals of time]
Notes:
Non-uniform motion refers to the motion where the objects cover equal distances in unequal time or unequal distances in equal time. In other words, when the speed of the object is not constant, or the direction of movement of an object changes, then it is in non-uniform motion. An example of this can be any vehicle moving on a crowded city road, where it constantly changes its speed.
7. As per the Newton’s second law of motion, what is the relation between the rate of change of linear momentum and the external force applied?
[A] directly proportional
[B] inversely proportional
[C] independent of each other
[D] None of the above
Show Answer
Correct Answer: B [inversely proportional]
Notes:
As per the Newton’s second law of motion, the rate of change of linear momentum of a body is inversely proportional to the external force applied on the body. This change always takes place in the direction of the force applied.
8. The work done in moving a body over a smooth inclined plane does not depend on which of the following?
[A] mass of the body
[B] height of the inclined plane
[C] slope of the inclined plane
[D] All of the above
Show Answer
Correct Answer: C [slope of the inclined plane]
Notes:
The work done in moving a body over a smooth inclined plane does not depend on the slope of the inclined plane. W = mgh in case of smooth inclined plane, where m = mass of the body, g = acceleration due to gravity and h = height of the inclined plane.
9. The energy by virtue of its position is known as:
[A] Kinetic energy
[B] Potential energy
[C] Internal energy
[D] Heat energy
Show Answer
Correct Answer: B [Potential energy]
Notes:
The energy by virtue of its position is known as Potential energy. The energy by virtue of its motion is known as Kinetic energy.
10. Kepler’s second law is also known as:
[A] Law of periods
[B] Law of areas
[C] Law of orbits
[D] Law of Planets
Show Answer
Correct Answer: B [Law of areas]
Notes:
Kepler’s second law states that an imaginary line joining a planet and the sun sweeps out an equal area of space in equal amounts of time i.e. the areal velocity of the planet around the sun is constant. It is also known as Law of areas.
