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LC Physics
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•Light
What is a self-luminous object?
An object that produces and emits its own light. Ex: the sun or a light bulb.
•Light
What is a non-luminous object?
An object that does not emit its own light. It can only be seen when it reflects light. Ex: the moon.
•Reflection & Mirrors
What is the first law of reflection?
The incident ray, the normal, and the reflected ray all lie in the same plane.
•Reflection & Mirrors
What is the second law of reflection?
The angle of incidence is equal to the angle of reflection. Symbolically, i = r.
•Refraction & Lenses
What is the first law of refraction?
The incident ray, the normal, and the refracted ray all lie in the same plane.
•Refraction & Lenses
What is the second law of refraction?
The sine of the angle of incidence is proportional to the sine of the angle of refraction. sin i / sin r = n.
•Light
What is the principle of reversibility of light?
Light travels the same path in reverse if its direction is reversed.
•Light
What is light?
Light is a form of energy that travels in straight lines at approximately 3 × 10⁸ m/s in a vacuum.
•Reflection & Mirrors
What is diffuse reflection?
Reflection from a rough surface where light is scattered in many directions.
•Reflection & Mirrors
What is regular reflection?
The bouncing of light from a smooth, shiny surface like a mirror, producing clear images.
•Reflection & Mirrors
What is the angle of incidence?
The angle between the incident ray and the normal at the point of incidence.
•Reflection & Mirrors
What is the angle of reflection?
The angle between the reflected ray and the normal at the point of reflection.
•Refraction & Lenses
What is the angle of refraction?
The angle between the refracted ray and the normal at the boundary of two media.
•Refraction & Lenses
What is the refractive index (n)?
The ratio of sin i to sin r. It measures how much light bends when entering a new medium.
•Reflection & Mirrors
What is the centre of curvature?
The centre of the sphere from which a mirror segment is taken. Denoted as C.
•Reflection & Mirrors
What is the pole of a mirror or lens?
The central point on the surface of a mirror or lens. Often denoted as P.
•Reflection & Mirrors
What is the radius of curvature?
The radius of the sphere of which the mirror is a part. R = 2f for spherical mirrors.
•Reflection & Mirrors
What is the principal axis?
A straight line passing through the centre of curvature and the pole of a mirror or lens.
•Reflection & Mirrors
What is the principal focus?
The point on the principal axis where parallel rays converge after reflection or refraction.
•Reflection & Mirrors
What is focal length?
The distance from the pole to the principal focus. For mirrors: f = R/2.
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•Reflection & Mirrors
What is a real image?
An image formed by actual convergence of rays. It can be projected onto a screen.
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•Reflection & Mirrors
What is a virtual image?
An image formed by apparent divergence of rays. It cannot be projected onto a screen.
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•Reflection & Mirrors
Where is the virtual image in a plane mirror?
On the perpendicular from the object to the mirror and the same distance behind the mirror.
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•Light
What is parallax?
The apparent motion of one object relative to another when the observer moves. Used to judge depth.
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•Light
What is a state of no parallax?
When two objects appear to remain aligned as the observer moves. They are at the same distance.
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•Reflection & Mirrors
What is lateral inversion?
The left-right reversal of an image in a mirror. Ex: the word 'ambulance' appears reversed.
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•Reflection & Mirrors
What is magnification?
The ratio of image height to object height. Magnification = image height / object height.
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•Refraction & Lenses
What is refraction?
Refraction is the bending of light as it passes from one medium to another with a different refractive index.
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•Refraction & Lenses
What is Snell’s Law?
The refractive index n = sin i / sin r when light moves from air into another medium.
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•Refraction & Lenses
What is the order of refractive index?
xny = 1 / ynx. It shows that refractive indices are reciprocal.
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•Refraction & Lenses
Refractive index in terms of light speed?
n = speed of light in air / speed of light in medium. Measures how much the light slows.
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•Refraction & Lenses
Refractive index using depths?
n = real depth / apparent depth. Used in experiments with glass blocks or water.
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•Refraction & Lenses
Refractive index using critical angle?
n = 1 / sin C, where C is the critical angle between the media.
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•Light
What is polarisation?
Restriction of transverse wave vibrations to one plane. Only possible with transverse waves.
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•Refraction & Lenses
What is the critical angle?
The angle of incidence in the denser medium that gives a 90° angle of refraction. Beyond this, total internal reflection occurs.
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•Refraction & Lenses
What is total internal reflection?
It occurs when light travelling from a denser to a rarer medium strikes the boundary at an angle greater than the critical angle, causing all light to reflect back into the denser medium.
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•Refraction & Lenses
What happens when two lenses are in contact?
Their powers add. The total power is the sum of the individual powers: P = P₁ + P₂. This affects overall focal length.
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•Refraction & Lenses
How is short sightedness corrected?
By placing a concave (diverging) lens in front of the eye to allow distant objects to focus on the retina. The condition occurs when the eyeball is too long.
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•Refraction & Lenses
What is an optical fibre?
A flexible glass strand with a high refractive index core and lower refractive index coating. It uses total internal reflection to guide light signals.
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•Waves & Wave Motion
What is the Doppler effect?
The apparent change in frequency of a wave due to relative motion between source and observer. Frequency increases as source approaches, decreases as it recedes.
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•Vibration & Sound
What are acoustics?
The study and control of sound reflection and absorption in enclosed spaces to produce clear sound quality. Used in concert halls and theatres.
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•Refraction & Lenses
What is the power of accommodation?
The eye's ability to change focal length by altering the shape of the lens to focus clearly on objects at different distances. P = 1/f.
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•Refraction & Lenses
What is the least distance of distinct vision?
The closest distance at which an object can be seen clearly without eye strain. For a normal eye, it's about 25 cm.
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•Refraction & Lenses
What is short sightedness?
A vision defect where nearby objects are clear, but distant objects appear blurred. Caused by an eyeball that's too long.
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•Refraction & Lenses
What is long sightedness?
A vision defect where distant objects are clear, but nearby ones appear blurred. Caused by an eyeball that's too short. Corrected with a convex lens.
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•Speed, Displacement, Velocity
What is speed?
The rate at which distance changes with time. Speed = distance / time. Scalar quantity.
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•Speed, Displacement, Velocity
What is instantaneous speed?
The speed of an object at a specific moment in time. Measured using small time intervals.
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•Speed, Displacement, Velocity
What is displacement?
The distance moved in a specific direction. It is a vector quantity.
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•Speed, Displacement, Velocity
What is velocity?
The rate of change of displacement with respect to time. Velocity = displacement / time. Vector quantity.
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•Speed, Displacement, Velocity
What is constant velocity?
When an object moves in a straight line with uniform speed, not accelerating or decelerating.
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•Acceleration
What is acceleration?
The rate of change of velocity with respect to time. Acceleration = Δv / t.
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•Vectors & Scalars
What is a scalar quantity?
A quantity that has magnitude only. Ex: mass, speed, temperature.
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•Vectors & Scalars
What is a vector quantity?
A quantity that has both magnitude and direction. Ex: velocity, force, displacement.
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•Force, Mass & Momentum
What is a force?
Anything that causes or has the potential to cause acceleration in an object. Measured in newtons (N).
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•Force, Mass & Momentum
What is a newton?
One newton is the force that gives a 1 kg mass an acceleration of 1 m/s².
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•Force, Mass & Momentum
What is mass?
The mass of an object is a measure of its resistance to acceleration (inertia). It does not change with location.
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•Force, Mass & Momentum
What is inertia?
The tendency of an object to resist a change in its state of motion. Directly proportional to mass.
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•Pressure, Gravity & Moments
What is weight?
The force due to gravity acting on a body. Weight = mass × gravitational field strength (g).
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•Force, Mass & Momentum
What is momentum?
Momentum = mass × velocity. It is a vector quantity and conserved in collisions.
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•Force, Mass & Momentum
What is impulse?
Impulse is the change in momentum. Impulse = force × time = Δmv.
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•Force, Mass & Momentum
What is Newton's First Law of Motion?
A body remains at rest or moves with constant velocity unless acted upon by an unbalanced external force.
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•Force, Mass & Momentum
What is Newton's Second Law of Motion?
The rate of change of momentum is proportional to the force applied, and takes place in the direction of the force. F = ma.
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•Force, Mass & Momentum
What is Newton's Third Law of Motion?
If object A exerts a force on object B, then B exerts an equal and opposite force on A.
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•Force, Mass & Momentum
What is the principle of conservation of momentum?
In a closed system, the total momentum before an interaction equals the total momentum after. No external force acts.
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•Pressure, Gravity & Moments
What is density?
Density is mass per unit volume. Formula: ρ = m / V. Unit: kg/m³.
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•Pressure, Gravity & Moments
What is pressure?
Pressure is force per unit area. Formula: P = F / A. Measured in Pascals (Pa).
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•Pressure, Gravity & Moments
What is the unit of pressure?
The pascal (Pa). One pascal = one newton per square metre (1 N/m²).
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•Pressure, Gravity & Moments
What is Archimedes' Principle?
A body immersed in fluid experiences an upthrust equal to the weight of fluid displaced.
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•Pressure, Gravity & Moments
What is the law of flotation?
A floating body displaces its own weight of fluid. The upthrust equals the body's weight.
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•Heat & Heat Transfer
What is Boyle’s Law?
At constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure.
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•Pressure, Gravity & Moments
What is Newton’s Law of Universal Gravitation?
Any two point masses attract with a force proportional to their masses and inversely proportional to the square of their separation.
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•Pressure, Gravity & Moments
What is the moment of a force?
It is the product of the force and its perpendicular distance from the axis of rotation. Moment = F × d.
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•Pressure, Gravity & Moments
What are the conditions for equilibrium?
1. Net force = 0. 2. Sum of clockwise moments = sum of anticlockwise moments.
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•Pressure, Gravity & Moments
What is a couple or torque?
Two equal and opposite forces whose lines of action do not coincide. Causes rotation only.
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•Work, Energy & Power
What is work?
Work is done when a force moves an object. Work = force × distance in direction of force.
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•Work, Energy & Power
What is the joule?
One joule is the work done when a force of 1 N moves an object 1 metre in the direction of the force.
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•Work, Energy & Power
What is energy?
Energy is the capacity to do work. All forms of energy can be converted but not created or destroyed.
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•Work, Energy & Power
What is the principle of conservation of energy?
Energy cannot be created or destroyed, only converted from one form to another.
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•Work, Energy & Power
What is kinetic energy?
Energy a body has due to motion. KE = ½mv².
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•Work, Energy & Power
What is potential energy?
Energy a body has due to its position or condition in a force field. Ex: PE = mgh in gravity.
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•Work, Energy & Power
What is a renewable energy source?
An energy source that is naturally replenished and not depleted by use. Ex: solar, wind.
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•Work, Energy & Power
What is power?
The rate at which work is done or energy is converted. Power = work/time.
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•Work, Energy & Power
What is the unit of power?
The watt (W). One watt is one joule per second.
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•Circular Motion
What is angular velocity?
The rate of change of angle with respect to time. Measured in radians per second (rad/s).
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•Circular Motion
What is the unit of angular velocity?
Radians per second (rad/s).
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•Circular Motion
What is centripetal force?
A force that keeps an object moving in a circular path. It acts towards the centre of the circle.
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•Circular Motion
What is centripetal acceleration?
The acceleration directed towards the centre of a circle for a body in circular motion. a = v²/r.
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•Circular Motion
What is the period of an orbit?
The time taken for a satellite to complete one full revolution around a planet. Measured in seconds.
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•Simple Harmonic Motion
What is Hooke’s Law?
The restoring force is proportional to displacement provided the elastic limit is not exceeded. F ∝ s.
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•Simple Harmonic Motion
When is a body in simple harmonic motion?
When its acceleration is proportional to displacement and directed towards a fixed point.
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•Simple Harmonic Motion
What is periodic time (T)?
Time taken for one complete oscillation in SHM. Measured in seconds.
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•Simple Harmonic Motion
What is frequency (f)?
The number of cycles per second. Measured in hertz (Hz). f = 1/T.
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•Temperature & Thermometers
What is temperature?
A measure of the hotness or coldness of a body. It determines the direction of heat flow.
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•Temperature & Thermometers
What is a thermometric property?
A physical property that changes measurably and uniformly with temperature. Used to build thermometers.
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•Heat & Heat Transfer
What is heat capacity?
The amount of heat energy needed to raise the temperature of an object by 1 kelvin. Unit: J/K.
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•Heat & Heat Transfer
What is specific heat capacity?
The heat energy required to raise the temperature of 1 kg of a substance by 1 kelvin. Unit: J/kg·K.
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•Heat & Heat Transfer
What is latent heat?
The heat energy required to change the state of a substance without a temperature change.
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•Heat & Heat Transfer
What is specific latent heat?
The heat required to change the state of 1 kg of a substance without changing its temperature. Unit: J/kg.
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•Heat & Heat Transfer
What is specific latent heat of fusion?
The amount of energy needed to convert 1 kg of a solid to liquid without changing its temperature.
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•Heat & Heat Transfer
What is specific latent heat of vaporisation?
The heat energy needed to convert 1 kg of liquid to gas at constant temperature.
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•Heat & Heat Transfer
What is conduction?
Transfer of heat through a solid by molecular vibrations. There is no movement of the material as a whole.
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•Heat & Heat Transfer
What is radiation (in heat transfer)?
The transfer of heat via electromagnetic waves. Can occur in a vacuum. Ex: heat from the sun.
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•Heat & Heat Transfer
What is convection?
Heat transfer in a fluid by movement of warmer, less dense regions rising and cooler regions sinking.
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•Heat & Heat Transfer
What is U-value?
Heat energy conducted per second through 1 m² of a material for each 1 °C temperature difference. Unit: W/m²K.
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•Heat & Heat Transfer
What is the solar constant?
The amount of solar energy per second hitting 1 m² at the edge of Earth’s atmosphere. Approx. 1.35 kW/m².
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•Waves & Wave Motion
What is a travelling mechanical wave?
A vibration that transfers energy through a medium without moving the medium overall. Ex: sound.
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•Waves & Wave Motion
What is a travelling wave?
A disturbance (mechanical or electromagnetic) that moves outwards from a source, transferring energy.
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•Waves & Wave Motion
What is a transverse wave?
A wave where the vibrations are perpendicular to the direction the wave travels. Ex: water waves, light.
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•Waves & Wave Motion
What is a longitudinal wave?
A wave where the vibrations are parallel to the wave direction. Ex: sound waves.
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•Waves & Wave Motion
What is amplitude?
The maximum displacement of a particle from its rest position. Related to wave energy.
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•Waves & Wave Motion
What is an oscillation or cycle?
One complete to-and-fro movement of the wave source. Forms the basis of frequency.
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•Waves & Wave Motion
What is wavelength?
The distance from one point on a wave to the next identical point. Ex: crest to crest.
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•Waves & Wave Motion
What is frequency?
The number of cycles per second. Unit: hertz (Hz). f = 1/T.
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•Waves & Wave Motion
What is wave velocity (c)?
The speed at which a wave travels. Formula: velocity = frequency × wavelength.
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•Waves & Wave Motion
What is reflection of waves?
The bouncing back of a wave when it hits a barrier. Obeys the law of reflection.
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•Waves & Wave Motion
What is refraction of waves?
A wave changing direction as it passes into a new medium with a different speed.
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•Waves & Wave Motion
What is diffraction?
The spreading out of waves as they pass through a gap or around an obstacle.
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•Waves & Wave Motion
What is interference?
When two waves meet, their displacements combine to form a new wave pattern.
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•Waves & Wave Motion
What is constructive interference?
Two waves meet in phase, and their displacements add to produce a larger amplitude.
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•Waves & Wave Motion
What is destructive interference?
Two waves meet out of phase, and their displacements partially or completely cancel.
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•Waves & Wave Motion
What are coherent sources?
Sources that produce waves of the same frequency and amplitude with a constant phase difference. Required for stable interference.
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•Waves & Wave Motion
What is an interference pattern?
The pattern formed when waves from coherent sources overlap, showing alternating regions of constructive and destructive interference.
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•Waves & Wave Motion
What is a stationary wave?
A wave pattern with fixed nodes and antinodes formed by interference of two identical waves moving in opposite directions.
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•Vibration & Sound
What are overtones?
Frequencies that are whole number multiples of a fundamental frequency. Ex: If f is fundamental, 2f is first overtone.
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•Vibration & Sound
What determines the loudness of a sound?
Loudness depends on the amplitude of the wave. Greater amplitude = louder sound. Frequency also plays a role.
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•Vibration & Sound
What determines the pitch of a note?
Pitch is determined by frequency. Higher frequency = higher pitch, lower frequency = lower pitch.
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•Vibration & Sound
What determines the quality of a musical note?
Quality (timbre) depends on the number and relative strengths of overtones present.
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•Vibration & Sound
What are the frequency limits of audibility?
The normal human ear can hear frequencies between 20 Hz and 20,000 Hz.
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•Vibration & Sound
What is resonance?
Resonance occurs when energy is transferred between bodies that have the same natural frequency, causing large amplitude vibrations.
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•Vibration & Sound
What is sound intensity at a point?
The rate of sound energy passing per unit area at right angles to the direction of travel. Unit: W/m².
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•Vibration & Sound
What is the threshold of hearing?
The lowest intensity detectable by the average human ear at 1 kHz, approximately 1 × 10⁻¹² W/m².
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•Vibration & Sound
What is the fundamental frequency of a string?
The lowest frequency at which a string vibrates. It has a node at each end and an antinode in the middle.
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•Vibration & Sound
What are harmonics?
Frequencies that are whole number multiples of a string's fundamental frequency. Ex: 2f, 3f, etc.
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•Light
What is a grating constant?
The distance between adjacent lines on a diffraction grating. Symbol: d.
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•Light
What is dispersion?
The splitting of light into its component wavelengths or colours. Occurs in prisms and diffraction gratings.
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•Light
What is a secondary colour?
A colour formed by mixing two primary colours in equal intensity. Ex: red + green = yellow.
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•Light
What is a complementary colour?
A primary colour and a secondary colour that combine to form white light. Ex: red and cyan.
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•Static Electricity
What is an insulator?
A material that does not allow electric charge to flow. Ex: plastic, glass.
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•Static Electricity
What is a conductor?
A material that allows electric charge to flow easily. Ex: metals like copper.
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•Static Electricity
What is static charge behaviour on conductors?
Charge resides on the outer surface and accumulates at sharp points. This is due to repulsion between like charges.
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•Static Electricity
What is Coulomb’s Law?
The force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
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•Static Electricity
What is the inverse square law in electrostatics?
If distance between two charges is doubled, the force becomes four times smaller; if trebled, nine times smaller.
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•Static Electricity
What is an electric field?
A region of space where a static charge experiences a force. It is caused by other static charges nearby.
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•Static Electricity
What is a line of force (electric field line)?
A line showing the direction a positive test charge would move in an electric field.
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•Static Electricity
What is electric field strength (E)?
The force per unit charge at a point in an electric field. E = F / q. Unit: N/C or V/m.
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•Potential Difference & Capacitance
What is potential difference?
The work done in moving a +1 C charge between two points in an electric field. Unit: volt.
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•Potential Difference & Capacitance
What is a volt?
One volt is the potential difference between two points when one joule of work is done in moving one coulomb between them.
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•Tags
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Answer
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•Potential Difference & Capacitance
What is potential at a point?
The potential difference between that point and the Earth. Measures how much work is needed to bring a +1 C charge from Earth to that point.
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•Potential Difference & Capacitance
What is capacitance?
The ratio of the charge on a conductor to its potential. C = Q/V. Unit: farad (F).
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•Potential Difference & Capacitance
What is a farad?
A conductor has a capacitance of 1 farad if placing a 1 C charge on it raises its potential by 1 V.
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•Current & Charge
What is electric current?
The flow of electric charge. Measured in amperes (A).
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•Current & Charge
What is the size of an electric current?
The amount of charge passing a point in a conductor per unit time. I = Q/t.
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•Electric Circuits
How is an ammeter connected in a circuit?
It must be connected in series with the component where current is to be measured.
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•Electric Circuits
What is voltage in series?
The total voltage across parts of a series circuit equals the sum of the voltages across each part.
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•Electric Circuits
What is voltage in parallel?
Each component in parallel has the same voltage across it. V₁ = V₂ = V₃.
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•Electric Circuits
How is a voltmeter connected in a circuit?
A voltmeter is connected in parallel with the part of the circuit where voltage is measured.
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•Potential Difference & Capacitance
What is electromotive force (E.M.F.)?
The total voltage supplied by a battery or cell when no current is flowing.
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•Resistance
What is resistance?
The ratio of potential difference to current in a conductor. R = V/I. Unit: ohm (Ω).
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•Resistance
What is 1 ohm?
A conductor has 1 ohm of resistance if a 1 A current flows through it when the voltage across it is 1 V.
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•Resistance
What is Ohm’s Law?
At constant temperature, the current through a conductor is directly proportional to the voltage across it.
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•Resistance
What is the rule for resistors in series?
Total resistance is the sum of individual resistances: R = R₁ + R₂ + R₃.
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•Resistance
What is Joule’s Law?
The rate of heat production in a conductor is proportional to the square of the current: P = I²R.
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•The Atom, Nucleus & Radioactivity
What is an ion?
An atom or molecule that has gained or lost electrons, giving it a positive or negative charge.
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•Work, Energy & Power
What is a kilowatt-hour?
The energy used by a 1000 W appliance running for one hour. 1 kWh = 3.6 million joules.
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•Semiconductors
What are holes (in semiconductors)?
Vacancies left behind when electrons break free from covalent bonds. They behave like positive charge carriers.
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•The Electron
What is thermionic emission?
The release of electrons from the surface of a hot metal due to thermal energy.
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•The Electron
What are cathode rays?
Streams of high-speed electrons travelling from the cathode in a vacuum tube.
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•The Electron
What is an electronvolt?
The energy gained or lost by an electron when it moves through a potential difference of 1 V. 1 eV = 1.6 × 10⁻¹⁹ J.
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•The Electron
What is the photoelectric effect?
Emission of electrons from a metal surface when exposed to electromagnetic radiation of suitable frequency.
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•The Electron
What is the work function (Φ)?
The minimum energy required to remove the most loosely bound electron from a metal's surface.
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•The Electron
What is a photon?
A packet of electromagnetic energy. Its energy is given by E = hf, where h is Planck’s constant and f is frequency.
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•The Atom, Nucleus & Radioactivity
What are X-rays?
High-frequency electromagnetic waves produced when high-speed electrons hit a metal target. Discovered by Röntgen.
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•The Atom, Nucleus & Radioactivity
What is alpha radiation?
Helium nuclei (2 protons, 2 neutrons) ejected from unstable nuclei. Least penetrating of the three types.
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•The Atom, Nucleus & Radioactivity
What is beta radiation?
Fast-moving electrons emitted from the nucleus of a radioactive atom during decay.
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•The Atom, Nucleus & Radioactivity
What is gamma radiation?
High-frequency electromagnetic radiation emitted from an atomic nucleus. Very penetrating and not deflected by fields.
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•Tags
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Answer
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•The Atom, Nucleus & Radioactivity
What is an emission spectrum?
A pattern of coloured lines formed when light from a luminous source is dispersed. Each line corresponds to a specific wavelength.
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•The Atom, Nucleus & Radioactivity
What is an energy level?
A fixed energy that an electron can have within an atom. Electrons move between levels by absorbing or emitting energy.
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•The Atom, Nucleus & Radioactivity
What is radioactivity?
The spontaneous breakdown of an unstable atomic nucleus with the emission of radiation such as alpha, beta, or gamma.
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•The Atom, Nucleus & Radioactivity
What is the activity of a radioactive source?
The number of nuclei decaying per second. Measured in becquerels (Bq).
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•The Atom, Nucleus & Radioactivity
What is the law of radioactive decay?
The number of nuclei decaying per second is directly proportional to the number of undecayed nuclei present.
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•The Atom, Nucleus & Radioactivity
What is one becquerel?
One becquerel (Bq) is one radioactive disintegration per second.
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•The Atom, Nucleus & Radioactivity
What is half-life?
The time it takes for half of the atoms in a radioactive sample to decay or for the activity to halve.
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•The Atom, Nucleus & Radioactivity
What was Rutherford's atom structure experiment?
Rutherford bombarded gold foil with alpha particles. Most passed through, some were deflected, and a few bounced back, indicating a dense nucleus.
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•The Atom, Nucleus & Radioactivity
How are line spectra formed in the Bohr model?
Electrons absorb energy and jump to higher levels. When they fall back, they emit light at specific frequencies, producing coloured lines.
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•The Atom, Nucleus & Radioactivity
What is a continuous spectrum?
A spectrum containing all wavelengths. Produced by hot solids or liquids. Ex: filament bulb.
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•The Atom, Nucleus & Radioactivity
What is a line spectrum?
A spectrum showing specific wavelengths emitted by excited atoms of a gas. Ex: sodium vapour lamp.
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•Particle Physics
What is an antiparticle?
A particle with the same mass but opposite charge to its corresponding particle. Ex: positron is the antiparticle of the electron.
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•Particle Physics
What is a positron?
The antiparticle of the electron. It has the same mass but a positive charge.
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•Particle Physics
What is antimatter?
Matter made of antiparticles, which have the same mass but opposite charge to normal particles.
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•Particle Physics
What is pair production?
The creation of a particle and its antiparticle from electromagnetic energy near a nucleus.
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•Particle Physics
What is pair annihilation?
The destruction of a particle and its antiparticle, converting their mass into electromagnetic energy.
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•Particle Physics
What is a lepton?
A fundamental particle that does not experience the strong nuclear force. Ex: electron, neutrino.
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•Particle Physics
What is a hadron?
A particle that experiences the strong nuclear force. Includes baryons and mesons.
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•Particle Physics
What is a baryon?
A hadron made of three quarks. Ex: proton and neutron.
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•Particle Physics
What is a meson?
A hadron made of a quark and an antiquark. Short-lived particles.
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•Particle Physics
What is a quark?
A fundamental particle with fractional electric charge. Combine to form hadrons.
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•Force, Mass & Momentum
What is a newton?
A force of 1 N gives a mass of 1 kg an acceleration of 1 m/s².
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•Nuclear Energy
What is nuclear fission?
The splitting of a large atomic nucleus into two smaller nuclei, releasing energy and neutrons. Ex: uranium-235.
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•Nuclear Energy
What is nuclear fusion?
The joining of two small nuclei to form a larger nucleus. Releases more energy than fission. Ex: hydrogen in the sun.
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•Force, Mass & Momentum
What is friction?
A force that opposes the relative motion of two surfaces in contact.
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