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. The value of acceleration due to gravity is __________?
[A] Minimum at equator and maximum at poles
[B] maximum at equator and minimum at poles
[C] equal at poles and equator
[D] None of the above
Show Answer
Correct Answer: A [Minimum at equator and maximum at poles]
Notes:
The value of acceleration due to gravity is maximum at equator. This is because the distance from the center is minimum at the equator.
2. The ideal fluid which is a hypothetical fluid should contain _______?
[A] Zero Viscosity Only
[B] Zero Compressibility Only
[C] Zero Viscosity & Zero Compressibility
[D] None of the above
Show Answer
Correct Answer: C [Zero Viscosity & Zero Compressibility]
Notes:
An ideal fluid hypothetical fluid should contain Zero Viscosity & Zero Compressibility. Almost all fluids will not have zero viscosity and zero compressibility.
3. If earth stops rotating, the impact on weight of a body will be minimum on which among the following places?
[A] Equator
[B] North Pole
[C] Tropic of Cancer
[D] Tropic of Capricorn
Show Answer
Correct Answer: B [North Pole]
Notes:
The question is related to the centrifugal forces, which represent the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation. The impact of this force is maximum at Equator and minimum at Pole.
4. What is the distance covered by a bus moving at a speed of 72 km/hr in a duration of 5 seconds?
[A] 50 meters
[B] 60 meters
[C] 74.5 meters
[D] 100 meters
Show Answer
Correct Answer: D [100 meters]
Notes:
The solution involves converting the speed of the bus from km/hr to m/sec. This conversion is achieved by the formula speed (m/sec) = speed (km/hr) * 5/18. Thus, the speed becomes 20 m/s. The distance travelled by the bus in 5 seconds is the product of speed and time which gives us 100 meters. Therefore, option [D] or option 4 is the correct answer.
5. A cardboard is placed on a glass of water, and a ten paise coin is placed on the cardboard. If the cardboard is flicked suddenly in the direction parallel to its surface, then the cardboard flies away, but the coin falls in the glass.
The behaviour of the coin can be explained by which among the following properties?
[A] Momentum
[B] Acceleration
[C] Inertia
[D] Friction
Show Answer
Correct Answer: C [ Inertia]
Notes:
Inertia is the property of matter that is why it continues in its existing state of either rest or motion. It can be changed by an external force. Here in the question the coin falls in the glass even after the cardboard is flicked because it maintains its rest position by the nature of inertia.
6. 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.
7. 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)
8. 1 nautical mile is equivalent to which of the following?
[A] 1.44 x 1000 m
[B] 1.852 x 100 m
[C] 1.852 x 1000 m
[D] 1.44 x 100 m
Show Answer
Correct Answer: C [ 1.852 x 1000 m ]
Notes:nautical mile is a unit of length. 1 nautical mile is equal to 1.852 x 1000 m Other important units of length are:
- 1 mile = 1.609 x 1000 m
- 1 light year = 9.46 x 1015 m
- 1 AU = 1.5 x 1011m
- 1 Par sec = 3.1 x 1016m
9. The acceleration at a given instant of time is called as:
[A] Average acceleration
[B] Instantaneous acceleration
[C] Variable acceleration
[D] Zero acceleration
Show Answer
Correct Answer: B [Instantaneous acceleration]
Notes:
The acceleration of an object at a given instant of time is called Instantaneous acceleration. When an object moves with variable acceleration, then it possesses different acceleration at different point of time.
10. Which of the following conditions is true for two vectors to be collinear?
[A] Equal magnitude
[B] Same Direction
[C] Acting along the parallel straight lines
[D] Both a and c
Show Answer
Correct Answer: C [Acting along the parallel straight lines]
Notes:
Two vectors are said to be collinear if they are acting along the parallel straight lines. The collinear vectors may or may not have equal magnitude.
