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 kinds of lenses are used to treat Astigmatism?
[A] Convex Lens
[B] Concave Lens
[C] Bifocal Lens
[D] Cylindrical
Show Answer
Correct Answer: D [Cylindrical]
Notes:
Astigmatism is due to imperfect spherical nature of eye lens. The focal length of eye lens is in two orthogonal directions become different so they cannot see objects in two orthogonal directions simultaneously. This defect in direction can be removed by using cylindrical lens in a particular direction.
2. 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.
3. Which among the following is the SI physical unit of dynamic viscosity?
[A] Poise
[B] Pascal-second
[C] Newton-second
[D] Poise-second
Show Answer
Correct Answer: B [Pascal-second]
Notes:
The SI unit for dynamic viscosity η is the Pascal-second (Pa-s). It corresponds to the force (N) per unit area (m2) divided by the rate of shear (s-1).
4. Two pieces of ice at 0°C would freeze together if pressed against each other and then released. In this context, which among the following is the correct principle in action in this?
[A] The melting point of pure ice decreases with pressure.
[B] The melting point of pure ice increases with Pressure
[C] The melting point of pure ice first increases, then decreases with pressure
[D] The melting point of pure ice first decreases then increases with pressure
Show Answer
Correct Answer: A [ The melting point of pure ice decreases with pressure.]
Notes:
Melting point of pure ice decreases with pressure at the rate of 0.0072°C per atmosphere and this is called regulation, which was discovered by Faraday and occurs at some 0°C or very slightly less temperature.
5. In which of the following conditions, a Balloon filled with a gas such as Hydrogen will tend to rise up?
[A] If the buoyant force exerted by the air on a balloon is greater than the weight of the balloon
[B] If the buoyant force exerted by the air on a balloon is less than the weight of the balloon
[C] If the buoyant force exerted by the air on a balloon is equal to the weight of the balloon
[D] If the density of the air is greater than the density of the gas filled in balloon
Show Answer
Correct Answer: A [ If the buoyant force exerted by the air on a balloon is greater than the weight of the balloon]
Notes:
A Balloon filled with a gas such as Hydrogen gas is much lighter in weight than the weight of air displaced by it. So the buoyant force exerted by the air on a balloon is greater than the weight of the balloon. The hydrogen gas which is lighter than air enables the balloon to float.
6. Which among the following Radio frequencies are used around the world in air navigational system?
[A] Very Low Frequency (VLF)
[B] Very High Frequency (VHF)
[C] Tetrahertz Radiation (THF)
[D] Ultra High Frequency (UHF)
Show Answer
Correct Answer: B [ Very High Frequency (VHF)]
Notes:
VHF (Very High Frequency) omnidirectional radio range (VOR), is a short-range radio navigation system for aircraft, enabling aircraft to determine their position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons, with a receiver unit. Uses radio frequencies in the very high frequency (VHF) band from 108 to 117.95 MHz. VOR is the standard air navigational system in the world, used by both commercial and general aviation.
7. Which of the following scientific discoveries was made by C.V Raman?
[A] Inelastic scattering of light by molecules
[B] Super Conductivity
[C] Controlled nuclear fission
[D] Cyclotron
Show Answer
Correct Answer: A [Inelastic scattering of light by molecules]
Notes:
C.V Raman discovered the Inelastic scattering of light by molecules in 1928, also named as ‘Raman effect’ Raman scattering is the inelastic scattering of a photon by molecules which are excited to higher vibrational or rotational energy levels. He was the first Indian Physicist to win the Nobel Prize for Physics in 1930. C.V Raman has also been bestowed with the Bharat Ratna Award.
8. What is the maximum height that can be attained by a projectile?
[A] equal to its maximum range
[B] one half of its maximum range
[C] one-fourth of its maximum range
[D] twice of its maximum range
Show Answer
Correct Answer: C [one-fourth of its maximum range]
Notes:
The maximum height that can be attained by a projectile is equal to one-fourth of its maximum range.
9. The centripetal force and centrifugal force are ______:
[A] equal in magnitude and have same direction
[B] unequal in magnitude and have same direction
[C] equal in magnitude and have opposite direction
[D] unequal in magnitude and have opposite direction
Show Answer
Correct Answer: C [equal in magnitude and have opposite direction]
Notes:
The centripetal force and centrifugal force are equal in magnitude and have opposite direction. Centrifugal force can be regarded as the reaction of centripetal force.
10. What is the product of the mass of the body and its velocity called as?
[A] Force
[B] Linear Momentum
[C] Energy
[D] Power
Show Answer
Correct Answer: B [Linear Momentum]
Notes:
Linear Momentum is the product of the mass of the body and its velocity. Linear Momentum (p) = mass(m) x velocity(v) p= mv Linear momentum is a vector quantity having the direction same as the direction of velocity of the body
