Basics of Physics MCQs for FPSC Meteorologist & Assistant Meteorologist 

Correct Answer: D

The Ideal Gas Law (PV = nRT) describes the relationship between pressure, volume and temperature of a gas, forming the theoretical basis for understanding how atmospheric pressure, density and temperature interact.

Correct Answer: C

Latent heat is the energy absorbed or released during a phase change, such as evaporation, condensation, freezing or melting, occurring without any change in temperature during the phase transition itself.

Correct Answer: D

The latent heat of vaporisation is the energy required to convert a given mass of liquid water into water vapour at a constant temperature, and its release during condensation is a key energy source for storms.

Correct Answer: A

Specific heat capacity is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree, and water’s high specific heat capacity explains why oceans moderate coastal climates.

Correct Answer: A

Adiabatic cooling occurs when rising air expands due to decreasing surrounding pressure, doing work on its environment and cooling as a result, without any direct exchange of heat with its surroundings.

Correct Answer: D

The dry adiabatic lapse rate is approximately 10 degrees Celsius per 1,000 metres (1 degree per 100 metres), describing how unsaturated rising air cools as it expands.

Correct Answer: C

The saturated adiabatic lapse rate is generally less than the dry rate because the latent heat released as water vapour condenses partially offsets the cooling caused by expansion.

Correct Answer: B

Atmospheric stability describes whether a parcel of air, once displaced vertically, tends to return to its original position (stable), continue rising or sinking (unstable), or remain in its new position (neutral).

Correct Answer: D

Unstable atmospheric conditions, where rising air continues to accelerate upward, favour the vigorous vertical development of convective clouds and thunderstorms.

Correct Answer: D

The Stefan-Boltzmann law states that the total energy radiated by an object is proportional to the fourth power of its absolute temperature, fundamental to understanding radiative heat transfer in the atmosphere.

Correct Answer: B

Wien’s Displacement Law states that the wavelength of peak radiation emitted by an object is inversely proportional to its temperature, explaining why the (hot) Sun emits mostly visible light while the (cooler) Earth emits mostly infrared.

Correct Answer: B

Atmospheric pressure in meteorology is commonly expressed in hectopascals (hPa), numerically equivalent to the older unit millibar (mb).

Correct Answer: D

The Doppler effect describes the change in the observed frequency of a wave caused by relative motion between the source (or a reflecting target) and the observer, exploited by Doppler radar to detect the motion of precipitation.

Correct Answer: C

Matter is classically described as existing in three basic states: solid, liquid and gas, each distinguished by the arrangement and movement of its constituent particles.

Correct Answer: C

Density is defined as an object’s mass divided by its volume, describing how tightly matter is packed within a given space.

Correct Answer: A

Newton’s First Law (the law of inertia) states that an object remains at rest or continues moving at constant velocity unless acted upon by an external unbalanced (net) force.

Correct Answer: D

Newton’s Second Law states that force equals mass multiplied by acceleration (F = ma), describing how the motion of an object changes under an applied force.

Correct Answer: C

Newton’s Third Law states that for every action force, there is an equal and opposite reaction force.

Correct Answer: C

The Newton (N) is the SI unit of force, defined as the force required to accelerate a mass of one kilogram at one metre per second squared.

Correct Answer: C

The Pascal (Pa) is the SI unit of pressure, defined as one Newton of force applied over an area of one square metre.

Correct Answer: D

The Joule (J) is the SI unit of energy, representing the work done when a force of one Newton moves an object one metre.

Correct Answer: B

Kinetic energy is the energy an object possesses because of its motion, and it increases with both mass and the square of velocity.

Correct Answer: B

Potential energy is stored energy related to an object’s position or state, such as gravitational potential energy, which depends on an object’s height above a reference point.

Correct Answer: A

The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed from one form into another, within a closed system.

Correct Answer: B

Refraction is the bending of a light wave as it passes from one transparent medium into another with a different optical density, such as from air into water.

Correct Answer: A

A rainbow forms when sunlight is refracted upon entering a raindrop, internally reflected off the back of the drop, and refracted again upon exiting, with the different wavelengths of light dispersing at slightly different angles to create the visible spectrum.

Correct Answer: A

Ohm’s Law states that voltage equals current multiplied by resistance (V = IR), a fundamental relationship in basic electrical circuits.

Correct Answer: A

Convection dominates within a boiling liquid, as warmer, less dense fluid rises while cooler, denser fluid sinks, creating a circulating current that transfers heat efficiently throughout the liquid.

Correct Answer: A

Frequency is the number of complete wave cycles that pass a given point in one unit of time, typically measured in Hertz (cycles per second).

Correct Answer: C

Wavelength is the physical distance between two successive corresponding points on a wave, such as from one crest to the next.

Correct Answer: A

Wave speed equals frequency multiplied by wavelength (v = f x lambda), a fundamental relationship applicable to all wave types including sound and electromagnetic waves.

Correct Answer: D

An object floats when its overall density is less than or equal to the density of the fluid it is placed in, in accordance with the principle of buoyancy (Archimedes’ Principle).

Correct Answer: B

Archimedes’ Principle states that the upward buoyant force acting on a submerged or floating object is equal to the weight of the fluid that the object displaces.

Correct Answer: D

At standard atmospheric pressure, water freezes at 0 degrees Celsius, equivalent to 32 degrees Fahrenheit.

Correct Answer: C

Boyle’s Law states that for a fixed quantity of gas at constant temperature, pressure and volume are inversely proportional: as volume decreases, pressure increases, and vice versa.

Correct Answer: A

Charles’s Law states that at constant pressure, the volume of a fixed quantity of gas is directly proportional to its absolute temperature: as temperature increases, volume increases proportionally.

Correct Answer: D

Weight is the force exerted on an object’s mass due to gravity, and therefore varies depending on the local gravitational field, unlike mass, which remains constant.

Correct Answer: D

Power is defined as the rate at which work is done or energy is transferred, measured as energy or work divided by the time taken, with the SI unit being the Watt.

Correct Answer: B

The laws of thermodynamics govern how energy, heat and work are transformed and transferred within physical systems, forming the theoretical foundation for understanding atmospheric heat exchange.

Correct Answer: D

The First Law of Thermodynamics states that energy cannot be created or destroyed, only converted between forms such as heat and work, within a closed system.

Correct Answer: D

Condensation, the change from vapour to liquid, releases latent heat into the surroundings, which is a major energy source powering storms and warming the atmosphere locally.

Correct Answer: B

Evaporation, the change from liquid to vapour, absorbs latent heat from its surroundings, which is why evaporative cooling makes the air near a wet surface feel cooler.

Correct Answer: B

Sublimation is the direct transition of a substance from solid to gas, bypassing the liquid phase entirely, as observed with dry ice or snow disappearing without visibly melting.

Correct Answer: A

Deposition is the direct transition from gas to solid, bypassing the liquid phase, as seen when frost forms directly from water vapour on a cold surface.

Correct Answer: B

A vacuum is a region of space essentially devoid of matter, including air, and therefore cannot support sound transmission or conduction/convection of heat.

Correct Answer: A

Sound is a mechanical wave requiring a medium (solid, liquid or gas) to propagate, so it cannot travel through a vacuum, unlike electromagnetic radiation such as light.

Correct Answer: B

The speed of sound in air at room temperature is approximately 340 metres per second, though it varies with temperature and the medium through which it travels.

Correct Answer: C

An echo results from sound waves reflecting off a distant surface and returning to the listener after a perceptible delay.

Correct Answer: A

The Hertz (Hz) is the SI unit of frequency, representing the number of complete wave cycles occurring per second.

Correct Answer: A

Unlike sound, electromagnetic radiation, including visible light, requires no medium and travels through a vacuum at the speed of light, approximately 300,000 kilometres per second.

Correct Answer: B

Infrared radiation has a longer wavelength than visible light, and is significant in meteorology since satellites use infrared sensors to detect cloud-top temperatures.

Correct Answer: B

Ultraviolet radiation has a shorter wavelength (and higher energy) than visible light, and is largely absorbed by the stratospheric ozone layer.

Correct Answer: B

The period of a simple pendulum depends primarily on its length and the local value of gravitational acceleration, and is essentially independent of the pendulum’s mass or amplitude for small swings.

Correct Answer: B

Static electricity arises from an imbalance of electric charge, often through friction, and its buildup and eventual discharge is the basic mechanism behind lightning within thunderstorm clouds.

Correct Answer: C

A capacitor stores electrical charge and energy within an electric field, and can release that stored energy rapidly, analogous in a very general sense to charge buildup in storm clouds before a lightning discharge.

Correct Answer: C

Terminal velocity is reached when the upward force of air resistance on a falling object exactly balances the downward force of gravity, so the object stops accelerating and falls at constant speed, relevant to raindrop and hailstone fall speeds.

Correct Answer: B

Surface tension arises from cohesive forces between liquid molecules at the surface, causing the surface to behave like a stretched elastic membrane and minimise its area, relevant to the shape of raindrops.

Correct Answer: C

Inertia is the inherent tendency of an object to resist any change in its state of motion, whether at rest or moving at constant velocity, as described by Newton’s First Law.

Correct Answer: B

Mass is a fundamental measure of the amount of matter contained in an object, and unlike weight, it does not change with location or gravitational field strength.

Correct Answer: D

The kilogram (kg) is the base SI unit of mass, from which other mass units such as the gram are derived.

Correct Answer: A

Volume is the amount of three-dimensional space occupied by an object or substance, measured in units such as cubic metres or litres.

Correct Answer: B

Acceleration is defined as the rate at which an object’s velocity changes over time, whether in speed, direction, or both.

Correct Answer: A

Velocity is a vector quantity, meaning it specifies both magnitude (speed) and direction, whereas speed is a scalar quantity specifying only magnitude.

Correct Answer: A

A scalar quantity is fully described by magnitude alone, such as mass or temperature, without any associated direction, unlike a vector quantity.

Correct Answer: A

A vector quantity requires both a magnitude and a direction to be fully specified, such as velocity, force, or displacement.

Correct Answer: B

Displacement is a vector quantity representing the straight-line distance and direction from a starting point to an ending point, which may be less than the total distance travelled along a curved or indirect path.

Correct Answer: A

Momentum is calculated as the product of an object’s mass and its velocity, and it is a key quantity conserved in collisions according to the law of conservation of momentum.

Correct Answer: C

The Law of Conservation of Momentum states that the total momentum of a closed system remains constant over time, provided no external unbalanced force acts upon it.

Correct Answer: D

Friction is a resistive force that opposes the relative motion or attempted motion between two surfaces in contact, converting some kinetic energy into heat.

Correct Answer: C

Kinetic or sliding friction acts on an object that is already moving relative to a surface, generally being somewhat less than the maximum static friction that must be overcome to start motion.

Correct Answer: D

Centripetal force acts toward the centre of a circular path, continuously changing the direction of a moving object’s velocity to keep it moving in a circle rather than a straight line.

Correct Answer: C

A lever is a rigid bar that pivots around a fixed point called the fulcrum, allowing a smaller applied force to move a larger load, or to change the direction of an applied force.

Correct Answer: B

A pulley uses a grooved wheel and rope or cable to change the direction of an applied force, and when used in combination, can also provide significant mechanical advantage for lifting heavy loads.

Correct Answer: D

Mechanical advantage is the ratio of the output force (load lifted or moved) to the input force (effort applied), indicating how much a machine multiplies an applied force.

Correct Answer: D

The centre of gravity is the point at which an object’s entire weight can be considered to act, useful for analysing balance and stability.

Correct Answer: C

An object in stable equilibrium, when slightly displaced, experiences a restoring force or torque that tends to return it to its original position.

Correct Answer: B

In physics, work is done when a force causes displacement of an object, calculated as the force multiplied by the displacement in the direction of the force.

Correct Answer: A

If an applied force produces no displacement of the object, no work is done in the physics sense, even if considerable effort or force was exerted, such as pushing against an immovable wall.

Correct Answer: B

An object’s inertia, its resistance to a change in motion, is directly related to its mass; more massive objects have greater inertia.

Correct Answer: A

A convex, or converging, lens is thicker at the centre than the edges and bends parallel light rays inward to converge at a focal point.

Correct Answer: A

A concave, or diverging, lens is thinner at the centre than the edges and causes parallel light rays to spread apart, appearing to originate from a virtual focal point.

Correct Answer: B

Reflection occurs when light rays strike a surface and bounce back, following the law of reflection where the angle of incidence equals the angle of reflection.

Correct Answer: D

A concave mirror curves inward and can converge reflected light rays, producing either a real, inverted image or a virtual, magnified image depending on the object’s distance from the mirror.

Correct Answer: A

A convex mirror curves outward and always produces a virtual, upright and reduced (smaller) image, regardless of the object’s distance, which is why they are used for wide-angle viewing such as vehicle side mirrors.

Correct Answer: C

The cornea and the lens of the eye work together to refract and focus incoming light onto the retina, forming a clear image.

Correct Answer: B

Dispersion occurs because different wavelengths of light refract by slightly different amounts when passing through a prism, causing white light to separate into its constituent spectrum of colours.

Correct Answer: A

An open circuit has a break or gap in its conductive path, preventing the flow of electric current, unlike a closed circuit which provides a complete path.

Correct Answer: B

In a series circuit, components are connected along a single path, so a break at any one point interrupts the entire circuit, stopping current flow throughout.

Correct Answer: D

In a parallel circuit, each branch provides an independent path for current, so a failure in one branch generally does not prevent current from flowing through the other branches.

Correct Answer: B

A conductor is a material, typically a metal, that allows electric current to flow through it with relatively little resistance, due to the free movement of electrons.

Correct Answer: C

An insulator is a material that strongly resists the flow of electric current, due to its electrons being tightly bound, making it useful for protecting against unwanted current flow.

Correct Answer: C

A magnetic field is the region of space surrounding a magnet or current-carrying conductor within which a magnetic force can be detected acting on other magnetic materials or moving electric charges.

Correct Answer: B

An electromagnet is formed by passing an electric current through a coil of wire, often wrapped around an iron core, generating a magnetic field that exists only while current flows.

Correct Answer: D

An electric generator operates on the principle of electromagnetic induction, converting mechanical energy (such as rotational motion) into electrical energy by moving a conductor through a magnetic field.

Correct Answer: B

An electric motor converts electrical energy into mechanical energy, typically producing rotational motion, the reverse process of an electric generator which converts mechanical energy into electricity.

Correct Answer: B

As temperature increases, most substances expand, increasing their volume while their mass remains essentially constant, which reduces their density; the reverse occurs on cooling.

Correct Answer: B

Thermal expansion describes how most materials change volume, typically expanding, in response to an increase in temperature, an important consideration in engineering and instrument design.

Correct Answer: B

Metals such as copper have high thermal conductivity, efficiently transferring heat through conduction, whereas materials like wood, air and rubber are relatively poor conductors (better insulators).

Correct Answer: A

A thermos flask uses a vacuum between double walls to virtually eliminate heat transfer by conduction and convection, combined with reflective surfaces to minimise radiative heat loss or gain.

Correct Answer: B

Dark or black surfaces absorb a greater proportion of incident radiation and are also more effective radiators of heat compared with light-coloured or shiny, reflective surfaces.

Correct Answer: B

Kinetic energy is calculated as one half multiplied by mass multiplied by velocity squared (KE = 1/2 m v²), showing that kinetic energy increases with the square of velocity.

Correct Answer: C

Gravitational potential energy is calculated as mass multiplied by gravitational acceleration multiplied by height (PE = mgh), representing stored energy due to an object’s position above a reference level.

Correct Answer: D

As an object falls under gravity, its gravitational potential energy progressively converts into kinetic energy, with the total mechanical energy remaining constant if air resistance is ignored.

Correct Answer: C

The electromagnetic spectrum, ordered from longest to shortest wavelength, runs: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and finally gamma rays with the shortest wavelength.

Correct Answer: C

Electromagnetic radiation energy increases as wavelength decreases, so the order of increasing energy runs from radio waves (lowest energy) through to gamma rays (highest energy).

Correct Answer: D

Specific gravity is the ratio of a substance’s density to the density of a reference substance, conventionally pure water at a specified temperature, giving a dimensionless value.

Correct Answer: A

As altitude increases, there is progressively less atmospheric mass above a given point, resulting in lower atmospheric pressure, a direct consequence of how pressure relates to the weight of overlying air.

Correct Answer: C

Hydraulic systems operate on Pascal’s Principle, which states that pressure applied to an enclosed incompressible fluid is transmitted undiminished throughout the fluid, allowing a small input force to generate a much larger output force.