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 of the following waves can be used to measure the speed of a approaching car?
[A] Light waves
[B] Micro waves
[C] Radio waves
[D] Sound waves
Show Answer
Correct Answer: C [Radio waves]
Notes:
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 gigahertz to as low as 30 hertz. It is used to measure the speed of an approaching car.
2. Which among the following provides the centripetal force to an electron circulating around the nucleus?
[A] electrostatic forces of repulsion
[B] electrostatic force of attraction
[C] speed of the electron
[D] nuclear charge
Show Answer
Correct Answer: B [electrostatic force of attraction]
Notes:
The correct answer is “electrostatic force of attraction.” In an atom, electrons are negatively charged and are attracted to the positively charged nucleus due to Coulomb’s law. This attraction provides the necessary centripetal force to keep the electron in a stable orbit around the nucleus. The balance between this electrostatic force and the electron’s inertia allows for stable atomic structures.
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 among the following property of the matter is studied in “Rheology”?
[A] Gravitation
[B] Viscosity
[C] Magnetic Properties
[D] Entropy
Show Answer
Correct Answer: B [Viscosity]
Notes:
Rheology is the study of the flow of matter, primarily in a liquid or gas state. It is related to Viscosity. In the science of rheology, a fluid’s changes are measured when there are actual forces (mechanical shear or pump pressure) induced.
5. A piece of Ice was tied with a string to a water bucket’s bottom, and the water bucket was filled with water with ice fully submerged in it. What would be the impact on the level of water when the ice melts away completely?
[A] The level of water will go up
[B] The level of water will go down
[C] The level of water will remain unchanged
[D] The level of water will first increase then come to the previous one
Show Answer
Correct Answer: B [ The level of water will go down]
Notes:
When Ice floats in water, the level of water will remain unchanged when the ice melts away because in this situation, Ice replaced water which is “equal to its weight”. But when the floating ice is taken down in the bottom of the bucket and tied over there with a string, and let melt away, the level of water will come down because now the ice was replacing the water “equal to its volume and Ice has a lower density of water. So The answer of this question is “The level of water will go down”.
6. 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.
7. Which of the following branch of Physics deal with study of Atomic Nuclei?
[A] Nuclear Physics
[B] Bio Physics
[C] Atomic Physics
[D] None of the above
Show Answer
Correct Answer: A [Nuclear Physics]
Notes:
Nuclear physics is a branch of physics that deals with the constituents, structure, behaviour and interactions of atomic nuclei. Atomic physics is a branch of physics that deals with the composition of the atom apart from the nucleus
8. Which of the these physical quantities is a vector quantity?
[A] Temperature
[B] Speed
[C] Gravitational Intensity
[D] Work
Show Answer
Correct Answer: C [Gravitational Intensity]
Notes:
The physical quantities which have both magnitude and direction are called as Vector quantities. Some examples of Vector quantities: Acceleration, Velocity, Torque, Displacement, Gravitational Intensity, Force.
9. What is the relation between velocity and acceleration at the highest point of projectile path?
[A] both are at an angle of 45° to each other
[B] both are perpendicular to each other
[C] both are at an angle of 180° to each other
[D] None of the above
Show Answer
Correct Answer: B [both are perpendicular to each other]
Notes:
At the highest point of projectile path, the velocity and acceleration are perpendicular to each other. At the highest point of projectile path, the projectile possesses velocity only along the horizontal direction.
10. As per the Newton’s second law of motion, what is the relation between the rate of change of linear momentum and the external force applied?
[A] directly proportional
[B] inversely proportional
[C] independent of each other
[D] None of the above
Show Answer
Correct Answer: B [inversely proportional]
Notes:
As per the Newton’s second law of motion, the rate of change of linear momentum of a body is inversely proportional to the external force applied on the body. This change always takes place in the direction of the force applied.
