Science and Technology, Grade 10: Key Terminology (Pressure, Fluid Mechanics, Heat, Light, and Electricity)

Vocabulary flashcards covering fundamental concepts from pressure, fluids, heat, light, optics, sound, electricity, and modern technology topics discussed in the Grade 10 science notes.

Pressure

Force per unit area exerted on a surface; SI unit is Pascal (N/m²); produced by solids’ weight or by fluids on walls.

Thrust

A force acting perpendicular to a surface; the normal component of contact force.

Fluid

A substance that can flow; includes liquids and gases.

Atmospheric pressure

Pressure exerted by Earth's atmosphere on surfaces and objects.

Normal force

Force exerted perpendicular to the surface of contact between two bodies.

Pascal's law

In a closed liquid, pressure is transmitted uniformly in all directions; basis for hydraulic devices: F1/A1 = F2/A2.

Hydraulic machine

Device that uses Pascal’s law to multiply force using fluids and pistons of different areas.

Hydraulic lift

Hydraulic device that amplifies force to lift heavy loads, e.g., car lift.

Hydraulic brake

Braking system that uses hydraulic fluid to transmit force to brake mechanisms.

Hydraulic jack

Hydraulic lifting device using fluid pressure and valves to lift heavy loads.

Hydraulic press

Machine that uses incompressible fluid to exert large force over a small piston.

Piston

Cylindrical component moving within a cylinder; transmits force via fluid.

Cross‑sectional area

Area of the piston face; pivotal in calculating pressure (P = F/A).

Transmission of pressure in liquids and gas

Spread of pressure through a liquid in an enclosed container, and in gas that is compressed

Fluid (as a state of matter)

Substance that can flow; includes liquids and gases.

Upthrust (U) and SI unit

Upward force exerted by a fluid on a submerged or floating object. SI unit is Newton

Why is there no tramission of pressure in a solid?

Solids cannot transmit pressure because their particles are closely packed and maintain fixed positions, restricting movement and flow.

Archimedes’ principle

Upthrust on a submerged object equals the weight of the displaced fluid.

Density

Mass per unit volume of a substance; influences buoyancy and upthrust.

Volume displaced

Volume of fluid displaced by an object submerged in it.

Apparent weight & formula

Weight of an object when submerged; real weight - upthrust.

Real weight

Weight of an object in air (true gravitational force on the object).

Ballast tank

Compartments in submarines used to adjust buoyancy by changing density.

Hydrometer

Instrument that measures relative density of liquids by buoyancy based on law of floatation or archimedes principle.

Lactometer

Hydrometer used to test the density of milk.

Upthrust equation

U = weight of displaced liquid.

Floatation (floatation principle)

Objects float when their weight equals the buoyant force from displaced liquid.

Law of floatation

An object floats if its weight equals the weight of the liquid it displaces.

Eureka can

A displacement can used to measure volume of displaced liquid in Archimedes’ experiments.

Weight, formula

Force due to gravity on an object; W = mg.

Specific heat capacity

Amount of heat needed to raise the temperature of 1 kg of a substance by 1°C (SI unit J/(kg·°C)).

Heat

Transfer of thermal energy from a body at higher temperature to a body at lower temperature; measured in joules.

Thermal energy, SI unit?

Sum of kinetic energy of all particles in a substance/body. SI is Joule

Calorimeter

Device used to measure the amount of heat absorbed or released during a process.

Heat equation

Q = m s ΔT; amount of heat (Q) = mass × specific heat capacity × change in temperature.

Mass

Amount of matter in an object; influences heat absorption via Q = msΔT.

Temperature

A measure of the average kinetic energy of the particles in a substance; determines heat flow.

Absolute zero

Theoretical temperature 0 K (−273.15°C), where molecular motion is at complete rest.

Kelvin scale

Thermodynamic temperature scale; zero kelvin corresponds to absolute zero.

Thermometer

Instrument used to measure temperature.

Liquid‑in‑glass thermometer

Thermometer using liquid (e.g., mercury) that expands with heat to indicate temperature.

Digital thermometer

Thermometer using thermistor or sensor to display temperature electronically.

Radiation thermometer

Thermometer that measures temperature from infrared radiation emitted by an object.

Calibration

Process of setting a thermometer’s scale using fixed reference points (0°C and 100°C for Celsius).

Fixed points (0°C, 100°C; 273 K, 373 K; 32°F, 212°F)

Conduction

Heat transfer through direct contact and molecule interaction within solids.

Convection

Heat transfer by movement of fluids (liquids/gases) carrying energy.

Radiation

Heat transfer through electromagnetic waves; does not require matter contact.

Heat vs temperature vs thermal energy

Heat is energy transfer; temperature is a measure of average kinetic energy; thermal energy is the total energy of all particles.

Refraction

Bending of light when it passes from one medium to another due to change in speed.

Snell’s law

sin(i)/sin(r) = μ (refractive index); relates incident and refracted angles across media.

Refractive index (μ)

Ratio of speed of light in vacuum (or air) to its speed in the medium; μ = c/v.

Critical angle

Angle of incidence for which the refracted ray is at 90° to the normal; induces total internal reflection.

Total internal reflection

Complete reflection of light within a denser medium when incident angle exceeds the critical angle.

Dispersion

Separation of white light into constituent colors when passing through a prism.

Visible spectrum

Seven colors of light (red, orange, yellow, green, blue, indigo, violet) visible to the eye.

VIBGYOR

Mnemonic for the colors of the visible spectrum.

Prism

Transparent optical element that disperses light into a spectrum.

Optical fibre

Thin flexible medium for light transmission; core surrounded by cladding to enable total internal reflection.

Core and cladding

Central glass (core) guides light; surrounding layer (cladding) with lower refractive index facilitates total internal reflection.

Convex lens

Thicker at the middle; converging lens that focuses parallel rays to a focal point.

Concave lens

Thinner at the center; diverging lens that causes parallel rays to appear to diverge from a focal point.

Focal length

Distance from the optical center to the focal point where rays converge (convex) or appear to diverge (concave).

Power of a lens

P = 1/f (dioptres); positive for converging lenses, negative for diverging lenses.

Optical centre

Geometric center of a lens where light rays pass undeviated.

Centre of curvature

Center of the sphere from which a lens surface is formed; influences curvature.

Radius of curvature

Distance from the centre of curvature to the lens surface.

Principal axis

Line through the optical centre and centers of curvature of a lens.

Real image

Image formed by converging rays that actually intersect; can be projected.

Virtual image

Image formed by diverging rays or by extending rays backward; cannot be projected.

Accommodation

Adjustment of the eye lens curvature by the ciliary muscles to focus on near/distant objects.

Myopia (shortsightedness)

Distant objects blur; corrected with a concave lens to diverge incoming rays.

Hypermetropia (longsightedness)

Nearby objects blur; corrected with a convex lens to converge rays.

Cataract

Clouding of the eye’s lens; sometimes treated with intraocular lens implantation (IOL).

Intraocular lens (IOL)

Artificial lens implanted after cataract removal to restore focusing power.

Color blindness

Inability to distinguish some colors due to cone cell defects, often hereditary.

Night blindness (nyctalopia)

Difficulty seeing in low light due to rod cell or vitamin A deficiencies.

Cornea

Transparent outer eye layer that provides most of the eye’s refractive power.

Pupil

Dark aperture that regulates light entering the eye; size controlled by iris.

Iris

Colored muscle surrounding the pupil; controls its size to regulate light entry.

Lens (eye lens)

Soft crystalline dish that focuses light onto the retina; adjustable by ciliary muscles.

Retina

Light-sensitive layer at the back of the eye containing rods and cones.

Rods and cones

Photoreceptor cells; rods enable vision in dim light; cones detect colors.

Magnetic field

Region around a magnet where magnetic forces can act; direction shown by field lines.

Maxwell’s right‑hand rule

Rule to determine the direction of magnetic field around a current-carrying conductor.

DC motor

A motor that converts electrical energy to mechanical energy under direct current.

AC generator (dynamo)

Device that converts mechanical energy to alternating current via rotating magnet and coil.

Transformer

Device using mutual induction to change AC voltage by differing turns in primary/secondary coils.

Primary and secondary coils

Coils in a transformer through which input and output AC voltages are applied.

Core lamination

Insulated metal sheets stacked to form the transformer core, reducing energy loss.

Baseband transmission

Digital signals transmitted over a channel without converting to analog.

Broadband transmission

Transmission of digital signals via conversion to analog for long-distance channels.

Digital signal

Signal represented by discrete values (e.g., binary 0 and 1) used in digital transmission.

Analog signal

Continuous signal that varies smoothly over time.

ADC (Analog-to-Digital Converter)

Device that converts continuous signals into digital form.

DAC (Digital-to-Analog Converter)

Device that converts digital data back into an analog signal.

Binary

Base-2 numeral system using two symbols: 0 and 1.

Bit

The smallest unit of data; either 0 or 1.

Byte

Group of 8 bits; a basic data unit.

Netizen

A person who participates online; an internet citizen.