Physics Big Bank

Definitions

Systematic Error

Systematic Errors are reproducible errors which results in a set of readings that is always smaller or always larger than the true value.

Random Error

Random Errors are unpredictable errors which results in a scattering of readings about a mean value

Precision

Precision refers to the closeness of a set of measurements

Accuracy

Accuracy refers to the degree of agreement between the measured value and the true value of a quantity

Scalar

Scalar Quantities are physical quantities that has a magnitude only

Vector

Vector Quantities are physical quantities that has both magnitude and direction

Distance

Distance is the total length travelled by a moving object irrespective of the direction of motion

Displacement

Displacement is the linear distance and direction an object is from a reference point

Speed

Speed is the rate of change of distance travelled by an object with respect to time

Velocity

Velocity is the rate of change of displacement of an object with respect to time

Acceleration

Acceleration is the rate of change of velocity of an object with respect to time

Vector

Vector Quantities are physical quantities that have both magnitude and direction

Newton’s First Law Of Motion

Newton’s First Law of Motion states that an object continues to be in a state of rest of uniform motion unless a resultant external force acts on it

Newton’s Second Law Of Motion

Newton’s Second Law of Motion states that the rate of change of momentum of a body is directly proportional to the resultant force acting on it and is in the direction of the resultant force

Newton’s Third Law of Motion

Newton’s Third Law of Motion states that when body A exerts a force on body B, body B will exert a force of equal magnitude in the opposite direction, on body A

Linear Momentum

Linear Momentum of a body is defined as the product of its mass and velocity

Impulse

The impulse of a force is defined as the product of the average force and the time interval during which the force is applied

Principle of Conservation of Linear Momentum

The Principle of Conservation of Linear Momentum states that the total linear momentum of a system remains constant unless a resultant external force acts on the system

Mass

Property of a body which resists the change in motion

Hooke’s Law

Hooke’s Law states that the change in the length of a material is directly proportional to the applied force, provided that the limit of proportionality is not exceeded.

Upthrust

Upthrust is the upward force exerted by a fluid on a submerged or floating object. It arises due to the difference in pressure between the upper and lower surfaces of the object

Archimedes Principle

Archimedes’ Principle states that for an object immersed in a fluid, the magnitude of the upthrust is equal to the weight of fluid displaced

Principle of Floatation

Principle of Flotation states that when an object floats in equilibrium, upthrust is equal to weight of the object

Moment / Torque

The moment / torque of a force about a point is defined as the product of the force and the perpendicular distance from the point to the line of action of the force

Couple

A pair of equal and opposite parallel forces whose line of action do not meet

Equilibrium

For a body in equilibrium, the resultant force is zero in all directions and the resultant moment is zero about any axis

Work

Work done by a force on a body is the product of the force and the displacement in the direction of the force

Principle of Conservation of Energy

Principle of Conservation of Energy states that energy can be converted from one form to another but it cannot be created or destroyed. The total energy of an isolated system is always constant

Power

Power is defined as the rate of work done or energy conversion with respect to time

Angular Displacement

The angular displacement of an object moving in a circle is defined as the angle through which the object turns, and is calculated by taking the ratio of arc length to the radius of the circle

Angular Velocity

Angular Velocity is the rate of change of angular displacement with respect to time

Gravitational Field

A Gravitational Field is a region of space in which a mass experiences a gravitational force.

Newton’s Law of Gravitation

Newton’s Law of Gravitation states that gravitational force between point masses is proportional to the product of their masses and inversely proportional to the distance between them squared.

Gravitational Field Strangth

Gravitational Field Strength at a given point in a gravitational field is the gravitational force per unit mass that acts on a small test mass placed at that point in the gravitation field

Gravitational Potential Energy

Gravitational Potential Energy of a mass at a point in a gravitational field is the work done, by an external force, in moving the mass from infinity to that point, without a change in kinetic energy.

Gravitational Potential

Gravitational Potential Energy of a mass at a point in a gravitational field is the work done per unit mass, by an external force, in moving a small test mass from infinity to that point, without a change in kinetic energy.

Geostationary Orbits

Satellites in G.O. rotate around the planet such that it is always positioned above the same point on the planet’s surface. They are vertically above the equator, move from west to eat and have an orbital period of 24 hours.

Temperature

Measure of average kinetic energy of molecules of a body

Thermal Equilibrium

For two bodies in thermal equilibrium, there is no net flow of thermal energy between them and they have the same temperature

Heat

Flow of internal Kinetic energy between two bodies due to their difference in temperature

Internal Energy

The internal energy of a system is the sum of its microscopic kinetic energies, due to the continuous random motion of molecules, and microscopic potential energy, due to their intermolecular forces.

Absolute / Kelvin Scale

Theoretical scale that is independent of the thermometric properties of any substance.

Absolute Zero

Temperature at which all substances have minimum internal energy (Note: Not zero internal energy!)

Ideal gas

An ideal gas satisfies the relationship of pV=nRT for all values of pressure, volume and temperature

Conditions where Real gas behaves ideally

1. High Temperature

2. High Pressure

Assumptions of Ideal Gas

1. Negligible IMFOA

2. Particles have negligible volume

3. Particles undergo elastic collisions

4. Duration of collisions is negligible compared to the time interval between collisions

Root-mean-square Speed

R.m.s speed of molecules is the value of speed that all molecules would possess at the same temperature if all the molecules possessed the same speed.

First Law of Thermodynamics

The First Law of Thermodynamics states that as a result of conservation of energy, the change in internal energy of a system through a process is equal to the sum of heat supplied to the system and the work done on the sytem.

Specific Heat Capacity

Amount og energy needed to produce a unit temperature change for a unit mass of a substance, without causing a change in state.

Specific Latent Heat of Fusion

Energy per unit mass required to change a substance from solid phase to liquid phase, or vice versa, without a change of temperature.

Specific Latent Heat of Vaporization

Energy per unit mass required to change a substance from liquid phase to gaseous phase, or vice versa, without a change of temperature.

Simple Harmonic Motion

A motion is simple harmonic if its acceleration is directly proportional to displacement and its acceleration and displacement are always in opposite directions.

Period

Time taken for one complete oscillation

Frequency

Number of complete oscillations per unit time

Amplitude

Maximum displacement from the equilibrium position

Damping

Damping refers to the loss of energy from an oscillating system to the environment, caused by a dissipative force acting in opposite direction of motion of the system

Light damping

The system oscillates about the equilibrium position with decreasing amplitude over time.

Critical damping

Critical damping occurs when a damping force causes a displaced body to not oscillate and damping is just adequate such that the system returns to its equilibrium position in the shortest possible time

Heavy damping

Heavy damping occurs when a damping force causes a displaced body to not oscillate and return to equilibrium position over a long time, longer than if the system was critically damped.

Forced oscillation

Forced oscillation is the phenomenon where an oscillating system is subject to an input of energy from an external periodic driving force. As a result, the frequency of the forced or driven oscillations will be at the frequency of the driving force

Natural Frequency

The frequency at which a system can receive energy at a maximum

Resonance

Resonance is a phenomenon whereby the amplitude of a system undergoing forced oscillations is at maximum. It occurs when the frequency of the periodic driving force is equal to the natural frequency of the system.

Progressive Wave

A progressive wave is the movement of a disturbance from a source which transfers energy from the source to places around it by means of vibrations/oscillations without transferring the medium itself

Transverse Wave

A transverse wave is a wave in which the oscillations of the wave particles are perpendicular to the direction of the propagation of the wave

Longitudinal Wave

A longitudinal wave is a wave in which the oscillations of the wave particles are parallel to the direction of the propagation of the wave

Wavelength

Distance between two consecutive points on a wave which are in phaseP

Phase

Phase is an angle which gives a measure of the fraction of a cycle that has been completed by an oscillating particle or by a wave.

One cycle corresponds to 2 pi radians

Intensity

Intensity is the rate of energy transfer per unit cross-sectional area perpendicular to the direction of wave propagation

Polarisation

Polarisation is the process by which the oscillations of the wave particles are restricted to only one plane normal to the direction of propagation.

Principle of Superposition

When two or more waves of the same types meet/superpose at a point, the resultant displacement of the waves is equal to the vector sum of their individual displacements at that point

Diffraction

Spreading of waves when they pass through an opening or when they pass round an obstacleC

Coherent Waves

Coherent waves have constant phase difference. They have the same speed, frequency and wavelength

Stationary Wave

Stationary Waves result from the superposition of two progressive waves of same frequency, amplitude and speed travelling along the same line but in opposite directions.

Node

The Node is a location in a stationary wave where particles no longer oscillate, typically when two waves reach the point pi radians out of phase

Antinode

The Antinode is a location ina stationary wave where the particles oscillate with maximum displacement, typically when two waves reach the point in phase

Electric Field

An electric field is a region of space in which an electric charge experiences an electric force

Coulomb’s law

Coulomb’s Law states that the magnitude of the electric force between two point charges is proportional to the product of their magnitude and inversely proportional to the distance between them squared.

Electric Field Strength

Electric Field Strength at a given point in an electric field is the electric force per unit charges that acts on a small positive test charge placed at that point in the electric field.

Electric Potential Energy

Electric Potential Energy of a charge at a point in an electric field is the work done, by an external force, in moving the charge from infinity to that point, without any change in kinetic energy.

Electric Potential

Electric Potential at a point in an electric field is the work done per unit charge, by an external force, in moving a small positive test charge from infinity to that point, without any change in kinetic energy.

Current

Rate of Flow of electric Charges

One Coulomb

A Coulomb is the quantity of electric charge that passes through a given point in a circuit when a steady current of one ampere flows through that point for one second.

Potential Difference

Potential Difference between two points in a circuit is the energy converted per unit electric charge from electrical energy to other forms of energy when the charge is moved between the two points.

One Volt

One Volt is the potential difference across two points in a circuit in which one joule of electrical energy is converted to other forms of energy when one coulomb of charge is moved between the two points.

Electromotive Force

Electromotive Force of a source is the energy converted per unit electric charge from other forms of energy to electrical energy in driving a charge round a complete circuit

Resistance

Resistance of a device is the ratio of the potential difference across to the current flowing through it

One Ohm

On Ohm is the resistance of a conductor through which a current of one ampere flows when a potential difference of one volt is applied across it

Ohm’s Law

Ohm’s Law states that the current I, through a metallic conductor is directly proportional to the potential difference V, across it, provided that the temperature and other physical conditions are kept constant.

Magnetic Field

A Magnetic Field is a region of space in which a magnetic material, a current-carrying conductor or a moving charge located in it may experience a force

Magnetic Flux Density

Magnetic Flux Density is defined as the force per unit length per unit current acting on a current-carrying conductor, placed perpendicular to the magnetic field.

One Tesla

A tesla is the magnetic flux density of a magnetic field when the force per unit length per unit current acting on a current-carrying conductor, placed perpendicular to the magnetic field is 1 Nm^-1 A^-1

Magnetic Flux

Magnetic Flux through a plane surface is the product of the magnetic flux density normal to the surface and the area of the surfaceO

One Weber

There is a magnetic flux of 1 Weber through a surface if a magnetic field of flux density of 1T exists perpendicularly to an area of 1 m²M

Magnetic Flux Linkage

Magnetic Flux Linkage through a loop is the product of the magnetic flux through the loop and the number of turns of wire in the loop.

Faraday’s Law

Faraday’s Law of Electromagnetic Induction states that the induced e.m.f in a conductor is directly proportional to the rate of change of magnetic flux linkage.

Lenz’s Law

Lenze’s Law of Electromagnetic Induction states that the polarity of the induced e.m.f is such that it produces a current that creates a magnetic field that opposes the change in magnetic flux linkage.

Alternating Current

Alternating Current occurs when charge carriers periodically reverse their direction of motion

Root-mean-square (rms) Current / Voltage

The r.m.s value of an alternating current / voltage is the value of a steady direct current / voltage that will dissipate energy at the same rate as the alternating current, in a given resistor.

Photon

A photon is a discrete packet (quanta) of electromagnetic radiation with energy proportional to its frequency

Photoelectric Effect

Photoelectric Effect is a phenomenon in which electrons are emitted from a cool metal surface when electromagnetic radiation of sufficiently high frequency is incident upon it