Physics MCQs

Correct Answer: Zero

The correct answer is Zero, as asked in this question on Physics.

Correct Answer: Antineutrino

The correct answer is Antineutrino, as asked in this question on Physics.

Correct Answer: Fusion Reaction

The correct answer is Fusion Reaction, as asked in this question on Physics.

Correct Answer: 3 × 10⁸ m/s

Light travels at about 3 × 10⁸ metres per second in a vacuum.

Correct Answer: Neutron

In modern physics, fundamental particles have no internal structure and cannot be divided further, such as quarks and neutrinos; protons and neutrons are composite particles made up of quarks, and the neutron is the commonly expected answer as not a fundamental particle.

Correct Answer: Back EMF

When an electric motor operates, it generates a back electromotive force (Back EMF) that opposes the applied voltage in accordance with Lenz's Law, produced by the motion of the motor's coils within a magnetic field and increasing with the speed of the motor.

Correct Answer: Decibel

The decibel (dB) is the internationally standard unit used to measure sound intensity level. It is a logarithmic unit that expresses the ratio of a sound's intensity relative to a reference level.

Correct Answer: Glass

Glass is primarily used in greenhouses because it allows sunlight (short-wave radiation) to enter but traps the infrared radiation (heat) emitted by the interior, creating a warm environment for plants.

Correct Answer: Antineutrino

During beta minus decay, a neutron turns into a proton, emitting an electron and an electron antineutrino.

Correct Answer: Fusion Reaction

The Sun generates energy through nuclear fusion, primarily fusing hydrogen nuclei into helium in its core.

Correct Answer: 3

The three primary states of matter are solid, liquid, and gas.

Correct Answer: Entropy

In thermodynamics, entropy is a measure of the disorder or randomness in a system.

Correct Answer: W/m²

The SI unit for sound intensity is Watts per square meter (W/m²).

Correct Answer: Faster

P (Primary) waves are longitudinal waves and travel faster than S (Secondary) waves, which are transverse.

Correct Answer: Antineutrino

In beta decay, a neutron converts into a proton, emitting an electron and an electron antineutrino.

Correct Answer: Fusion

The Sun generates energy through nuclear fusion, primarily converting hydrogen into helium.

Correct Answer: 10%

Nuclear power currently provides approximately 10% of the world's total electricity production.

Correct Answer: T4

According to the Stefan-Boltzmann law, the total energy radiated per unit surface area of a black body (like a star) is proportional to the fourth power of its temperature (T4).

Correct Answer: Silver

The correct answer is Silver, as asked in this question on Physics.

Correct Answer: Distance

The correct answer is Distance, as asked in this question on Physics.

Correct Answer: Electromagnetism

A galvanometer is an electromechanical instrument for detecting and measuring electric current based on electromagnetic principles.

Correct Answer: Zero

At the peak of its trajectory, the ball momentarily stops before changing direction, making its vertical velocity zero.

Correct Answer: Mechanical Energy

Mechanical energy is the sum of an object's kinetic and potential energy.

Correct Answer: Temperature of liquids

A thermos flask is designed to minimize heat transfer, thereby keeping liquids hot or cold for an extended period.

Correct Answer: Meters per second (m/s)

The SI unit for speed is meters per second (m/s).

Correct Answer: Same for all intensities

In a vacuum, all electromagnetic waves travel at the same constant speed (the speed of light), regardless of their frequency or intensity.

Correct Answer: Mechanical

An electric generator functions by converting mechanical energy (rotational motion) into electrical energy through electromagnetic induction.

Correct Answer: Condensation

Condensation is the phase change of matter from gas (vapor) to liquid.

Correct Answer: White

White objects reflect all wavelengths of visible light, making them the most effective at reflecting sun rays.

Correct Answer: 331 m/s

The speed of sound in dry air at 0°C is approximately 331.3 meters per second.

Correct Answer: Steel

Sound travels fastest through solids like steel because the particles are more closely packed compared to liquids or gases.

Correct Answer: Henri Becquerel

Henri Becquerel discovered radioactivity in 1896 through his experiments with uranium salts.

Correct Answer: Preventing the tracks from bending due to heat expansion

The gaps in railway tracks allow for thermal expansion during hot weather, preventing the tracks from buckling or bending.

Correct Answer: Water is denser than ice

Water expands when it freezes, making ice less dense than liquid water, which allows it to float.

Correct Answer: No unit

Specific gravity is a dimensionless quantity, defined as the ratio of the density of a substance to the density of a reference substance (usually water).

Correct Answer: Copper

Copper is commonly used for transformer windings due to its high electrical conductivity, which minimizes energy loss.

Correct Answer: Galvanometer

A galvanometer is an instrument used for detecting and measuring small electric currents, not for measuring pressure.

Correct Answer: A liquid turns into a vapors

Vaporization is a phase transition from the liquid phase to the vapor or gaseous phase.

Correct Answer: Fission

Nuclear fission is the process used in nuclear reactors to release energy by splitting atoms.

Correct Answer: Velocity

Velocity is a derived unit (meters per second), whereas meter, Kelvin, and candela are base SI units.

Correct Answer: Solid particles

In solids, particles are tightly packed and vibrate in fixed positions rather than moving freely around.

Correct Answer: Atomic Bomb

Nuclear fission is the process of splitting an atomic nucleus into two or more smaller nuclei, which is the underlying mechanism of atomic bombs.

Correct Answer: Internal Heat

The energy required to raise the temperature of a body is related to its internal heat capacity.

Correct Answer: 10^-6 meters

One micrometer, also known as a micron, is defined as one millionth of a meter, or 10^-6 meters.

Correct Answer: Stock value

Acceleration, inertia, and motion are fundamental concepts in physics, whereas 'stock value' relates to finance.

Correct Answer: Displacement

Displacement is a vector quantity defined as the shortest straight-line distance between two points.

Correct Answer: Archimedes' Principle

Submarines control buoyancy to submerge or surface based on Archimedes' principle, which relates to displacement and buoyant force.

Correct Answer: Radiation

Radiation is the transfer of energy via electromagnetic waves, which does not require a medium.

Correct Answer: Inertia

Inertia is the tendency of an object to resist changes in its state of motion, as described in Newton's first law of motion.

Correct Answer: Isaac Newton

Sir Isaac Newton formulated the Law of Universal Gravitation in his work 'Philosophiæ Naturalis Principia Mathematica'.

Correct Answer: Thermodynamics

Refrigerators operate on the principles of thermodynamics, specifically the refrigeration cycle involving heat exchange.

Correct Answer: Radiation

Radiation is the transfer of energy through electromagnetic waves, which does not require a material medium.

Correct Answer: Conservation of Momentum

Rocket propulsion is fundamentally governed by the principle of conservation of momentum and Newton's third law of motion.

Correct Answer: 32 °F

On the Fahrenheit scale, water freezes at 32 degrees and boils at 212 degrees at standard atmospheric pressure.

Correct Answer: Seven

The SI system consists of seven base units: meter, kilogram, second, ampere, kelvin, mole, and candela.

Correct Answer: 746 W

In mechanics, one standard mechanical horsepower is equivalent to approximately 745.7 watts, which is rounded to 746 watts.

Correct Answer: Chemical Energy

Coal contains stored chemical energy, which is released as thermal energy (heat) when it is combusted.

Correct Answer: Ampere

The ampere (often shortened to 'amp') is the SI base unit of electrical current.

Correct Answer: Convex

Convex mirrors are used as rear-view mirrors in vehicles because they give a wider field of view.

Correct Answer: Store electrical energy

A capacitor is a passive two-terminal electrical component used to store energy electrostatically in an electric field.

Correct Answer: Temperature

Celsius is an SI-derived unit used globally to measure and express temperature.

Correct Answer: Gravity

Gravity is the fundamental natural force by which physical bodies with mass—like the Earth—attract other objects toward their centers.

Correct Answer: Scattering

Rayleigh scattering causes shorter (blue) wavelengths of sunlight to scatter more effectively through Earth's atmosphere, making the sky appear blue.

Correct Answer: Newton

Sir Isaac Newton is credited with formulating the law of universal gravitation.

Correct Answer: Geiger counter

A Geiger counter is an instrument used to detect and measure ionizing radiation.

Correct Answer: Diffusion

Diffusion is the net movement of particles from a region of higher concentration to one of lower concentration.

Correct Answer: 9%

When water transforms into ice, it expands by approximately 9% due to the formation of a crystalline structure.

Correct Answer: Steel

Elasticity is defined by a material's ability to return to its original shape; steel is more elastic than rubber according to Young's Modulus.

Correct Answer: Density

Ice is less dense than liquid water, which allows it to float.

Correct Answer: Generator

An electrical generator operates on the principle of electromagnetic induction to convert rotational mechanical energy into electrical energy.

Correct Answer: Hertz

The frequency of all electromagnetic waves, including radio waves, is measured in Hertz (Hz), which represents cycles per second.

Correct Answer: Silicon

Silicon is a highly pure semiconductor material that serves as the foundation for modern electronics, including transistors and integrated circuits.

Correct Answer: Higher frequency

The pitch of a sound is determined by its frequency. Women's vocal cords produce sounds at a higher frequency, resulting in a higher pitch (shrill voice).

Correct Answer: Iron, Nickel and Cobalt

Iron, nickel, and cobalt are ferromagnetic materials that are strongly attracted to magnets.

Correct Answer: Angstrom

An angstrom is a unit of length equal to 10⁻¹⁰ meters.

Correct Answer: 7

When white light passes through a prism, it undergoes dispersion and splits into seven colors: red, orange, yellow, green, blue, indigo, and violet.

Correct Answer: Sublimation

Sublimation is the phase transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.

Correct Answer: Theory of special relativity

Albert Einstein's Theory of Special Relativity (1905) revolutionized physics by intertwining space and time into a single continuum.

Correct Answer: Thermal Energy

Nuclear fission releases a large amount of heat, which is classified as thermal energy, used to generate steam for electricity production.

Correct Answer: Electrical energy

A solar cell (photovoltaic cell) is an electronic device that converts the energy of light directly into electricity via the photovoltaic effect.

Correct Answer: Discovery of the neutron

Sir James Chadwick was awarded the 1935 Nobel Prize in Physics for his 1932 discovery of the neutron, a subatomic particle with no electric charge.

Correct Answer: Distance

A light-year measures the total distance that light travels in a vacuum within the span of one Julian year.

Correct Answer: Joule

In the International System of Units (SI), heat energy is measured in Joules (J).

Correct Answer: Mechanical wave

Sound requires a medium (solid, liquid, or gas) to propagate, classifying it as a mechanical wave.

Correct Answer: 1945

Key nuclear physics models evolved heavily around 1945 during the conclusion of the Manhattan Project and global focus on atomic physics.

Correct Answer: Atmospheric pressure

The boiling point of any liquid drops as atmospheric pressure decreases, which is why water boils at a lower temperature at high altitudes.

Correct Answer: Solid

Sound waves propagate significantly faster in solids than in liquids or gases because the molecules in a solid are packed much more tightly together.

Correct Answer: Speed

Speed is a scalar quantity as it relies only on magnitude, unlike velocity or displacement which also possess direction.

Correct Answer: All of these

Matter commonly exists in three classical states: solid, liquid, and gas.

Correct Answer: Total Internal Reflection

Optical fibers transmit data by repeatedly bouncing light off the fiber walls, utilizing a physics phenomenon known as total internal reflection.

Correct Answer: Michael Faraday

Michael Faraday discovered electromagnetic induction in 1831, proving that a changing magnetic field can induce an electric current in a circuit.

Correct Answer: Transparent objects

Transparent materials, like clear glass, allow light to pass through them completely, making objects on the other side clearly visible.

Correct Answer: Velocity

In physics, velocity is defined as a vector quantity that represents the rate of change of displacement over time.

Correct Answer: -196°C

Liquid nitrogen boils at approximately -196°C at atmospheric pressure.

Correct Answer: Geiger-Muller counter

A Geiger-Muller counter is a standard instrument used for detecting and measuring ionizing radiation.

Correct Answer: Water

Swimmers use a streamlined posture to minimize drag (friction) while moving through the water.

Correct Answer: 760 mm

Standard atmospheric pressure is defined as 760 mm of mercury (Hg) at sea level.

Correct Answer: Nuclear energy

Radioactivity is a process by which an unstable atomic nucleus loses energy by radiation, originating from nuclear sources.

Correct Answer: Red, Green & Blue

The primary colors of light in the additive color model (RGB) are Red, Green, and Blue.

Correct Answer: Axis of rotation

An axis of rotation is a straight, imaginary line around which a three-dimensional body or object rotates.