Gce O Level Physics Definitions

A quantity that can be measured, consisting of a numerical magnitude and a unit.

A complete to-and-fro movement of an object.

The time taken for one complete oscillation.

Physical quantities that have magnitude only.

Physical quantities that have both magnitude and direction.

The distance moved per unit time.

Rate of change of displacement.

The rate of change of velocity.

The state of an object where its weight is equal to the air resistance against it.

Every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.

When a resultant force acts on an object of a constant mass, the object will accelerate in the direction of the resultant force. The product of the mass and acceleration of the object gives the resultant force.

For every action, there is an equal and opposite reaction.

The contact force that opposes or tends to oppose motion between surfaces in contact.

The amount of matter in a body.

The gravitational force, or gravity, acting on an object.

A region in which a mass experiences a force due to gravitational attraction.

The gravitational force acting per unit mass.

The reluctance of an object to change its state of rest or motion, due to its mass.

The product of the force F and the perpendicular distance d from the pivot to the line of action of the force.

When a body is in equilibrium, the sum of clockwise moments about a pivot is equal to the sum of anti-clockwise moments about the same

pivot .

The point through which the whole weight of an object appears to act.

The ability to do work.

Energy cannot be created or destroyed, but can be converted from one form to another. The total energy in an isolated system is constant.

The product of the force and the distance moved by the object in the direction of the force.

The rate of work done or rate of energy conversion.

The force acting per unit area.

Refers to how hot or cold an object is.

R efers to the amount of thermal energy that is being transferred from a hotter to a colder region.

The lower fixed point. It is the temperature of pure melting ice at one atmosphere, and it is assigned a value of 0°C.

The upper fixed point.It is the temperature of steam from water boiling at one atmosphere, and is assigned a value of 100°C.

The theory that the tiny particles that make up matter are always in continuous random motion.

The transfer of thermal energy through a medium without any flow of the medium.

The transfer of thermal energy by means of convection current in a fluid (liquid or gas), due to a difference in density.

The transfer of thermal energy in the form of electromagnetic waves such as infrared radiation without the aid of a medium.

The amount of thermal energy required to raise the temperature of a substance by 1K.

The amount of thermal energy required to raise the temperature of a unit mass of a substance by 1K.

The energy released or absorbed by a substance during a change of state, without a change in its temperature.

The amount of thermal energy required to change a substance from one solid state to liquid state, without a change in temperature.

The amount of thermal energy required to change unit mass of the substance from solid state to liquid state, without a change in temperature.

The amount of thermal energy require to change a substance from liquid state to gaseous state, without a change in temperature.

The amount of thermal energy require to change unit mass of a substance from liquid state to gaseous state, without a change in temperature.

The incident ray, reflected ray and the normal at the point of incidence all lie in the same plane.

The angle of incidence i is equal to the angle of reflection r.

The bending of light as it passes from one optical medium to another.

The angle of incidence in an optically denser for which the angle of refraction in the optically dense medium is 90°.

The complete reflection of a light ray side an optically denser medium at its boundary with an optically less dense medium.

The distance between the optical centre C and the focal point f.

Waves that travel perpendicular to the direction of the vibration.

Waves that travel parallel to the direction of the vibration.

The maximum displacement of a point from its rest position.

The shortest distance between any two points in phase.

The tim taken to produce one complete oscillation.

The number of complete waves produce per second.

The distance travelled by a wave per second.

An imaginary line on a wave that joins all adjacent points that are in phase.

A form of energy that is transferred from one point to another as a longitudinal wave.

The repetition of a sound due to the refection of sound

A sound with frequencies above the upper limit of the human range of audibility

Related to the frequency of a sound wave - the higher the frequency, the higher the pitch

Related to the amplitude of a sound wave - the larger the amplitude, the louder the sound

The attractive or repulsive force that electric charges exert on one another

A region in which an electric charge experiences an electric force

Rate of flow of electric charge Q

The work dome by the source in driving a unit charge around a complete circuit

The work done to drive a unit charge through the component

The ratio of the potential difference V across it to the current I flowing through it

The current passing through a metallic conductor is directly proportional to the potential difference across it, provided that physical conditions remain constant

A line of resistors connected in series. It is used to provide a fraction of the voltage of a source to another part of the circuit

Electronic devices that convert non-electrical energy to electrical energy

The region surrounding a magnet, in which a body of magnetic material experiences a magnetic force.

A current-carrying conductor experiences a force when placed in a magnetic field

The process through which an induced e.m.f. is produced in a conductor due to a changing magnetic field

The magnitude of the induced e.m.f. in a circuit is directly proportional to the rate of change of magnetic flux in the circuit

The direction of the induce e.m.f., and hence the induce current in a closed circuit is always such that its magnetic effect opposes the motion or change producing it

A device that can change a high alternating current (at low current) to a low alternating voltage (at high current), or vice versa