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. Any moving object on earth finally comes to rest due to which among the following?
[A] Gravity
[B] Friction
[C] Inertia
[D] Motion
Show Answer
Correct Answer: B [Friction]
Notes:
Friction is the main reason for any object to come to rest. It is the main reason for the stability of the objects on earth.
2. 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
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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.
3. Mach number is a measure of which of the following?
[A] Speed
[B] Heat Transfer
[C] Static Pressure
[D] Volume
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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.
4. Which among the following correctly represents a Parsec?
[A] 0.326 Light Years
[B] 3.261 Light Years
[C] 32.61 Light Years
[D] 3.026 Light Years
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Correct Answer: B [3.261 Light Years]
Notes:
One parsec is approximately equal to 31 trillion kilometres (19 trillion miles), or 210,000 astronomical units, and equates to about 3.3 light-years.
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
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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. Who among the following is credited for the Corpuscular theory of light?
[A] Isaac Newton
[B] Christiaan Hyugens
[C] Albert Einstein
[D] James Clerk Maxwell
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Correct Answer: A [Isaac Newton]
Notes:
The Corpuscular theory of light was given by Isaac Newton. It was replaced by Huygens’ wave theory when it failed to adequately explain the diffraction, interference and polarization of light. The Huygens’ wave theory was replaced by Planck’s quantum theory and finally de-Broglie’s Dual-Theory of light replaced all previous ones.
7. Who was the first scientist to discover Electrons?
[A] Albert Einstein
[B] Isaac Newton
[C] J.C. Bose
[D] J.J Thompson
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Correct Answer: D [J.J Thompson]
Notes:
J.J Thompson was the first scientist to discover and identify the electrons and to make the discovery of the first subatomic particle. He was also the first scientist to find evidence for isotopes of a stable (non-radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). His experiments to determine the nature of positively charged particles led to the development of the mass spectrograph. J.J Thompson belonged to United Kingdom. He won the Nobel Prize in Physics in 1906 for his work on the conduction of electricity in gases.
8. Which of the following units is NOT used for measuring length?
[A] Astronomical Unit
[B] Light year
[C] Par sec
[D] slug
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Correct Answer: D [ slug ]
Notes:
Astronomical Unit, Light year and Par sec are the units used to measure very large distances whereas slug is a unit to measure heavy masses. 1 slug = 14.57 kg
9. What should be the angle between force and displacement for maximum work to be done?
[A] 0°
[B] 90°
[C] 180°
[D] 30°
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Correct Answer: A [0°]
Notes:
For maximum work, the angle between force and displacement should be 0°. W = Fs Cos 0° = Fs For zero work, the angle between force and displacement should be 90°. W = Fs Cos 90° = 0
10. What is the effect of increase in radius of orbit on the binding energy of a satellite?
[A] it increases
[B] it decreases
[C] It remains the same
[D] None of the above
Show Answer
Correct Answer: B [it decreases]
Notes:
The binding energy of a satellite decreases with the increase in the radius of orbit. The binding energy of a satellite is inversely proportional to the radius of orbit.
