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. Zero point energy is the lowest possible energy that a quantum mechanical physical system may have. “Who among the following proposed this concept?
[A] Max Planck
[B] Albert Einstein and Otto Stern
[C] Hendrik B. G. Casimir
[D] Gribbin, John
Show Answer
Correct Answer: B [Albert Einstein and Otto Stern]
Notes:
Albert Einstein and Otto Stern proposed the concept of Zeropoint energy. It is the lowest possible energy that a quantum mechanical physical system may have.
2. Fermi-Kurie plot is used for the study of which of the following?
[A] Alpha Decay
[B] Beta Decay
[C] Internal Conversion
[D] Cluster Decay
Show Answer
Correct Answer: B [Beta Decay]
Notes:
Fermi–Kurie plot is a graph developed by Franz N. D. Kurie and is used in studying beta decay. In this graph square root of the number of beta particles whose energy lie within a specific range, divided by the Fermi function, is plotted against beta-particle energy.
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. 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.
5. 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.
6. The frequency range of Ultra High Frequency (UHF) is __?
[A] 3 to 10 Megahertz
[B] 3 to 30 Megahertz
[C] 300 to 3000 Megahertz
[D] 300 to 30000 Megahertz
Show Answer
Correct Answer: C [ 300 to 3000 Megahertz]
Notes:
Ultra High Frequency (UHF) designates the ITU radio frequency range of electromagnetic waves between 300 Megahertz to 3 GHz (3,000 Megahertz).
7. Which of the following is not a valid conservation law of classical Physics?
[A] Law of conservation of energy
[B] Law of conservation of current
[C] Law of conservation of angular momentum
[D] Law of conservation of charge
Show Answer
Correct Answer: B [Law of conservation of current]
Notes:
The following laws are dealt with in the classical physics: 1. Law of conservation of energy 2. Law of conservation of angular momentum 3. Law of conservation of linear momentum 4. Law of conservation of charge
8. Which of the following is correct about the properties of Gravitational Forces?
[A] They are the strongest forces in nature
[B] They observe inverse square law
[C] Both a and b
[D] None
Show Answer
Correct Answer: B [They observe inverse square law]
Notes:
Gravitational Forces are the weakest forces in nature. They obey inverse square law as they vary inversely as the square of the distance between the two bodies. They are central forces and conservative forces. They operate over very long distances having an infinite range.
9. What is the time taken by the earth to complete one rotation about its axis with regard to a fixed star?
[A] Sidereal day
[B] Solar day
[C] Shake
[D] Tropical year
Show Answer
Correct Answer: A [Sidereal day]
Notes:
Sidereal day is the time taken by the earth to complete one rotation about its axis w.r.t a fixed star Solar day is the time taken by the earth to complete one rotation about its axis w.r.t the sun. Shake is the smallest practical unit of time 1 shake = 10-8s Tropical year: The year in which there is a total solar eclipse.
10. Which of the following is the unit of Impulse?
[A] N
[B] Ns
[C] N/s
[D] Ns2
Show Answer
Correct Answer: B [ Ns ]
Notes:
The unit of impulse is Ns. Impulse = Force(N) x Time(s) Impulse can be defined as the integral of a force, F, over the time interval, t, for which it acts.
