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 kinds of lenses are used to treat Astigmatism?
[A] Convex Lens
[B] Concave Lens
[C] Bifocal Lens
[D] Cylindrical
Show Answer
Correct Answer: D [Cylindrical]
Notes:
Astigmatism is due to imperfect spherical nature of eye lens. The focal length of eye lens is in two orthogonal directions become different so they cannot see objects in two orthogonal directions simultaneously. This defect in direction can be removed by using cylindrical lens in a particular direction.
2. Which of the following term denotes the internal reaction force per unit area developed as a result of applied external force ?
[A] Stress
[B] Friction
[C] Moment of Inertia
[D] tension
Show Answer
Correct Answer: A [Stress]
Notes:
Stress is the force acting per unit area. It is the internal force reaction per unit area developed as a result of external force.
3. At which of the following places water shall boil at the lowest temperature?
[A] Kochi
[B] Ooty
[C] Mount Abu
[D] New Delhi
Show Answer
Correct Answer: B [Ooty]
Notes:
This question is related to Antoine equation. Water to get boil, its vapour pressure must reach to its surrounding pressure. In a pressure cooker, it boils at the highest temperature. Elevation of Kochi is 0 m, ooty is 2,486 m, Mount Abu is 1,200 m, New Delhi is 216 m, Shimla is 2,205 m. So comparing all of them, water will boil at lowest temperature at ooty, followed by Shimla, Mount Abu , New Delhi and Kochi. This is because , higher we go lower is the atmospheric pressure and lower is the point where water`s vapour pressure gets equal to the atmospheric pressure.
4. Which among the following is the correct sequence of the terms used for various phases of the rocky object from space entering earth’s atmosphere and reaching on earth?
[A] Meteoroid – Meteor – Meteorite
[B] Meteorite – Meteoroid – Meteor
[C] Meteor – Meteorite – Meteoroid
[D] Meteoroid – Meteorite – Meteor
Show Answer
Correct Answer: A [ Meteoroid – Meteor – Meteorite]
Notes:
A meteoroid is a small rocky or metallic body travelling through space. When such an object enters the Earth’s atmosphere, it heats up from atmospheric friction and produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor, or colloquially a “shooting star” or “falling star”. If a meteoroid, comet or asteroid or a piece thereof withstands ablation from its atmospheric entry and impacts with the ground, then it is called a meteorite. (Wikipedia)
5. Which of the following is an example of application of force?
[A] when a body at rest starts moving
[B] when a moving body stops
[C] when moving body changes its direction
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Force can be defined as an external effort in the form of push or pull which: (i) Produces or tries to produce motion in a resting body (ii) Stops or tries to stop a moving body (iii) Changes or tries to change the direction of motion of the body
6. 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.
7. The minimum speed required to put a satellite into a given orbit around earth is known as:
[A] Escape velocity
[B] Orbital velocity
[C] Kinetic velocity
[D] None of the above
Show Answer
Correct Answer: B [Orbital velocity]
Notes:
The minimum speed required to put a satellite into a given orbit around earth is known as Orbital velocity of the satellite. Orbital velocity (v) = (GM/r)1/2 where G= gravitational constant, M= mass of the earth and r = radius of the orbit of the satellite.
8. Which of the following strains is produced in a body if the deforming force produces a change in the shape of the body without changing its volume?
[A] Linear
[B] Volumetric
[C] Shearing
[D] All of the above
Show Answer
Correct Answer: C [Shearing]
Notes:
If the deforming force produces a change in the shape of the body without changing its volume, the strain produced in the body is called as shearing strain. Shearing strain is defined as angle in radians through which a plane perpendicular to the fixed surface of the cubical body gets turned under the effect of tangential force.
9. Which of the following factors do not affect the value of modulus of elasticity of a body?
[A] Nature of material
[B] Temperature of the body
[C] Length and volume and of the body
[D] None of the above
Show Answer
Correct Answer: C [Length and volume and of the body]
Notes:
Modulus of elasticity (E) depends upon the nature of material of the body and the manner in which the body is deformed. Modulus of elasticity (E) depends upon the temperature of the body. Modulus of elasticity (E) is independent of the dimensions (length, volume etc.) of the body
10. 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.
