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 defines gravitational mass?
[A] Ratio of weight of a body and acceleration due to gravity
[B] Ratio of Acceleration due to gravity and weight of a body
[C] matter contained in a body
[D] None of the above
Show Answer
Correct Answer: A [Ratio of weight of a body and acceleration due to gravity]
Notes:
Gravitational mass is the Ratio of weight of a body and acceleration due to gravity. Gravitational mass is the mass of a body as measured by its gravitational attraction for other bodies.
2. Mach number is a measure of which of the following?
[A] Speed
[B] Heat Transfer
[C] Static Pressure
[D] Volume
Show Answer
Correct Answer: A [Speed]
Notes:
Mach number refers to the ratio of the velocity of a fluid to the velocity of sound in that fluid, named after Ernst Mach (1838–1916), an Austrian physicist and philosopher. Speed of sound is Mach 1 speed.
3. 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.
4. Edwin Howard Armstrong was an inventor of which of the following technologies?
[A] Television
[B] Compact Discs
[C] FM Radio
[D] Broadband
Show Answer
Correct Answer: C [FM Radio]
Notes:
Edwin Howard Armstrong was an American electrical engineer who developed FM radio and the superheterodyne receiver system. Edwin Howard Armstrong is the “father of FM radio” and was born in 1890.
5. In context with electromagnetism, which among the following is a correct definition of Permeability?
[A] Ability of a material to repel magnetic field within itself
[B] Ability of a material to support the formation of a magnetic field within another body
[C] Ability of a material to support the formation of a magnetic field within itself
[D] Ability of a material to create magnetic dipoles
Show Answer
Correct Answer: C [Ability of a material to support the formation of a magnetic field within itself]
Notes:
Ability of a material to support the formation of a magnetic field within itself is Permeability. It is the measure of the resistance of a material against the formation of a magnetic field.
6. Which of the following makes a CD or DVD show rainbow pattern?
[A] Diffraction of the Light
[B] Thin-Film Interference of the light
[C] Scattering of the light
[D] Polarisation of the light
Show Answer
Correct Answer: A [ Diffraction of the Light]
Notes:
A CD or DVD has closely spaced tracks which work as a diffraction grating to form the familiar rainbow pattern seen when looking at a disk.
7. Who gave the Theory of Relativity?
[A] Isaac Newton
[B] Archimedes
[C] Albert Einstein
[D] Galileo Galilei
Show Answer
Correct Answer: C [Albert Einstein]
Notes:
Albert Einstein was the founder of Theory of Relativity. According to Einstein’s theory, mass m is equivalent to energy E given by the relation E = mc^2 where c is speed of light in vacuum. Albert Einstein was awarded the 1921 Nobel Prize in Physics for his contribution to the field of Theoretical Physics.
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. A projectile will achieve maximum horizontal range at which angle?
[A] 90°
[B] 60°
[C] 45°
[D] 30°
Show Answer
Correct Answer: C [45°]
Notes:
A projectile will achieve maximum horizontal range when it is projected at an angle of 45°. This concept of maximum horizontal range is used by athletes in long jump, javelin throw, cricket ball throw etc
10. What is the unit of intensity of Gravitational field in the c.g.s system?
[A] dyne cm g-1
[B] dyne g-2
[C] dyne cm g2
[D] dyne g-1
Show Answer
Correct Answer: D [dyne g-1]
Notes:
The unit of intensity of Gravitational field in the c.g.s system is dyne g-1 or cm s-2. S.I. unit of intensity of Gravitational field is N Kg-1 m s-2.
