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 would be most commonly affected, if the filament of a electric Bulb is not uniform?
[A] Light
[B] Life
[C] Resistance
[D] None of the above
Show Answer
Correct Answer: B [Life]
Notes:
If the filament of the bulb is affected then the life of the bulb is affected. Filament is very important for the bulb to function.
2. Who among the following is known to manufacture first Cyclotron?
[A] Ernest Lawrence
[B] Niels Bohr
[C] Rutherford
[D] Max Born
Show Answer
Correct Answer: A [Ernest Lawrence]
Notes:
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. A cyclotron accelerates charged particles outwards from the center along a spiral path.
3. “Fermi” is a unit of which among the following?
[A] Mass
[B] Length
[C] Velocity
[D] Frequency
Show Answer
Correct Answer: B [Length]
Notes:
“Fermi” is the unit of length. The femtometre is an SI unit of length equal to 10⁻¹⁵ metres, which means a quadrillionth of one.
4. Which of the following waves is called compression-dilation waves or longitudinal waves?
[A] Primary waves
[B] Secondary waves
[C] Love waves
[D] Rayleigh waves
Show Answer
Correct Answer: A [Primary waves]
Notes:
Primary wave is also called compression-dilation or longitudinal waves. Secondary wave is called transversal wave. Love wave and Rayleigh wave are surface waves. P waves can pass through solid, liquid and gases and are also the fastest among the three main types of waves.
5. 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)
6. What is the range of masses involved in the study of Physics?
[A] 10-19 kg to 1038 kg
[B] 10-30 kg to 1055kg
[C] 10-30 kg to 1030kg
[D] 10-19 kg to 1055 kg
Show Answer
Correct Answer: B [10-30 kg to 1055kg]
Notes:
The range of masses involved in the study of Physics ranges from 10-30 kg to 1055 kg. 10-30kg is the mass of an electron and 1055 kg is the mass of known observable universe. The range of time scale involved in the study of Physics ranges from 10-22 s to 1018 s. The range of length involved in the study of Physics ranges from 10-14m to 1026 m.
7. 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.
8. What is the work done by centripetal force in case of Uniform Circular Motion?
[A] 1 joule
[B] 0 joule
[C] Depends on the magnitude of Force
[D] None of the above
Show Answer
Correct Answer: B [0 joule]
Notes:
The work done by Centripetal Force in case of Uniform Circular Motion is zero. The displacement and force are mutually perpendicular to each other in case of centripetal force. Therefore the work done is zero.
9. What is the relation between Time period and Frequency in case of uniform circular motion?
[A] reciprocal to each other
[B] equal to each other
[C] no relation between them
[D] Time period is one half of the Frequency
Show Answer
Correct Answer: A [reciprocal to each other]
Notes:
Time period and Frequency are reciprocal to each other in case of uniform circular motion. Time period = 1 /Frequency Time Period is the time taken by the object to complete one revolution. Frequency is the number of revolutions completed by the object in unit time.
10. What is the angular acceleration of a body moving with constant angular velocity?
[A] equal to the angular velocity
[B] 1
[C] 0
[D] Can’t be determined
Show Answer
Correct Answer: C [0]
Notes:
The angular acceleration of a body moving with constant angular velocity is 0. Angular acceleration of an object in circular motion is defined as the time rate of change of its angular velocity.
