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. What happens when a ship enters a Sea from a river ?
[A] It rises
[B] It remains at the same level
[C] sinks a little
[D] None of the above
Show Answer
Correct Answer: A [It rises]
Notes:
When a ship enters a sea from a river ,the ship is elevated or uplifted due to the density of sea water and during the buoyant motion of the ship, as it would gain both potential and kinetic energy when rising in the fluid.
2. 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.
3. 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.
4. Which among the following strictly works on the principle of dipole movement of the water molecules?
[A] Refrigerator
[B] Microwave Oven
[C] Air Conditioner
[D] Electric Geyser
Show Answer
Correct Answer: B [Microwave Oven]
Notes:
Microwave Oven strictly works on the principle of dipole movement of water molecule. A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.
5. The term “Isopycnic” is most closely defined by which among the following?
[A] Two places with same atmospheric pressure
[B] Two liquids with same viscosity
[C] Two liquids with same density
[D] Two places with same temperature
Show Answer
Correct Answer: C [Two liquids with same density]
Notes:
The term “Isopycnic” refers to two substances having the same density. It is derived from the Greek words “iso,” meaning equal, and “pycnos,” meaning dense. In scientific contexts, isopycnic conditions are often used in centrifugation techniques to separate particles based on their density, such as in the purification of DNA or proteins.
6. In recent times, the “dynamic brake system” is becoming popular in modern railways. The dynamic brake system coverts Kinetic energy to__:
[A] Potential energy
[B] Electricity
[C] Sound energy
[D] Magnetic energy
Show Answer
Correct Answer: B [ Electricity]
Notes:
Modern engines also have, additionally, dynamic brake system which works on the principle of converting kinetic energy of the moving train to electricity making the electric motors to work as generators.
7. In which among the following, the speed of sound would be maximum?
[A] Dry air at 0°C
[B] Dry air at 30°C
[C] Humid air at 0°C
[D] Humid air at 30°C
Show Answer
Correct Answer: D [ Humid air at 30°C]
Notes:
The speed of sound in a medium depends on temperature of the medium. The speed of sound decreases when we go from solid to gaseous state. In any medium as we increase the temperature the speed of sound increases.. The speed of sound will be highest in humid air at 30°C.
8. If a Candle is make to burn in Zero Gravity__:
[A] The Candle will burn for a very long time compared to normal gravity
[B] The flame of the candle will become round
[C] There is no impact of gravity on the burning of candle
[D] The Candle will not burn in zero gravity
Show Answer
Correct Answer: B [ The flame of the candle will become round]
Notes:
Gravity plays a role in flame formation. Modifying the gravity causes different flame types. The common distribution of a flame under normal gravity conditions depends on convection, as soot tends to rise to the top of a general flame, as in a candle in normal gravity conditions, making it yellow. In micro gravity or zero gravity, such as an environment in outer space, convection no longer occurs, and the flame becomes spherical, with a tendency to become more blue and more efficient (although it may go out if not moved steadily, as the CO2 from combustion does not disperse as readily in micro gravity, and tends to smother the flame).
9. 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
10. Which of the following physical quantities has no units?
[A] Reynold Number
[B] Rydberg constant
[C] Wave number
[D] Hubble constant
Show Answer
Correct Answer: A [ Reynold Number ]
Notes:Reynold Number has no units. The Reynolds number is the ratio of inertial forces to viscous forces. It is used for predicting if a flow condition will be laminar or turbulent.
- Unit of Rydberg constant: m-1
- Unit of Wave number = m-1
- Unit of Hubble constant = sec-1
