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 eye defect causes image focus in front of the retina?
[A] Presbyopia
[B] Hypertropia
[C] Myopia
[D] Hyperopia
Show Answer
Correct Answer: C [Myopia]
Notes:
Myopia (short-sightedness) occurs when images are focused in front of the retina, causing distant objects to appear blurry. It is commonly due to an elongated eyeball or excessive corneal curvature. This defect is corrected using concave (diverging) lenses. Hyperopia, by contrast, focuses images behind the retina.
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. 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.
4. The term “Isopycnic” is most closely defined by which among the following?
[A] Two places with same atmospheric pressure
[B] Two liquids with same viscosity
[C] Two liquids with same density
[D] Two places with same temperature
Show Answer
Correct Answer: C [Two liquids with same density]
Notes:
The term “Isopycnic” refers to two substances having the same density. It is derived from the Greek words “iso,” meaning equal, and “pycnos,” meaning dense. In scientific contexts, isopycnic conditions are often used in centrifugation techniques to separate particles based on their density, such as in the purification of DNA or proteins.
5. Which among the following is measured by an Odometer?
[A] Pressure
[B] Height
[C] Distance
[D] Velocity
Show Answer
Correct Answer: C [Distance]
Notes:
An odometer is an instrument used for measuring the distance. It measures distance traveled by a vehicle such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two.
6. A long Rail (approximately 700 meters) made up of steel is struck to produce a sound. The person standing on the other end of the rail would hear in which among the following pattern?
[A] He listens the sound waves once propagated via steel
[B] He listens the sound waves once propagated via air
[C] He listens the sound waves twice, first propagated via steel and second propagated via air
[D] He listens the sound waves twice, first propagated via air and second propagated via steel
Show Answer
Correct Answer: C [He listens the sound waves twice, first propagated via steel and second propagated via air]
Notes:
The correct answer is that the person hears the sound waves twice: first via steel and then via air. Sound travels faster in solids than in gases. in steel, it travels at about 5,960 m/s, while in air, it travels at approximately 343 m/s. Given the long distance of 700 meters, the sound will reach the person through the steel rail first, followed by the sound traveling through the air. This phenomenon illustrates the differences in sound propagation speeds in different media.
7. With reference to the nuclear energy, what is the Special Nuclear Material (SNM)?
[A] A nuclear material that is NOT capable of sustaining a chain reaction of nuclear fission
[B] A fissile material that is capable of sustaining a chain reaction of nuclear fission
[C] A fissile material that is NOT capable of sustaining a chain reaction of nuclear fusion
[D] A fissile material that is capable of sustaining a chain reaction of nuclear fusion
Show Answer
Correct Answer: B [ A fissile material that is capable of sustaining a chain reaction of nuclear fission]
Notes:
A nuclear fissile material that is capable of sustaining a nuclear reaction is called Special Nuclear Material.
8. One joule of work is said to be done when__:
[A] a force of 1 dyne causes a displacement of 1 cm.
[B] a force of 1 dyne causes a displacement of 1 m.
[C] a force of 1 N causes a displacement of 1 cm.
[D] a force of 1 N causes a displacement of 1 m.
Show Answer
Correct Answer: D [ a force of 1 N causes a displacement of 1 m.]
Notes:
The joule is the unit of energy in the International System of Units. It is equal to the work done on an object when a force of one Newton acts on that object in the direction of the force’s motion through a distance of one meter. One joule of work is said to be done when a force of 1 N causes a displacement of 1 m.
9. What is the apparent weight of the person when the elevator is accelerating downwards?
[A] equal to the actual weight
[B] greater than the actual weight
[C] less than the actual weight
[D] 0
Show Answer
Correct Answer: C [less than the actual weight]
Notes:
The apparent weight of the person becomes less than the actual weight when the elevator is accelerating downwards. The apparent weight of the person becomes more than the actual weight when the elevator is accelerating upwards.
10. 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.
