Definitions Flashcards
Define Absolute Error?
Absolute Error is the difference between a measured value and the true value.
Define Percentage Error?
(Absolute Error / True value) x 100
Define Random Error?
Random Error is error that does not follow any consistant pattern.
Define Systematic Error?
Systematic Error is error that has a consistant pattern.
Define Absolute Uncertainty?
Absolute Uncertainty is the interval in which the true value is expected to lie.
Define Percentage Uncertainty?
(Absolute Uncertainty / True value) x 100
Define Parralax Error?
Parralax Error is a form of systematic error, which is caused by the angle of the observer.
Define Anomalous Results?
Anomalous Results are results which don’t fit the pattern of the rest of the data.
Define Newton’s First Law of Motion?
An object will remain at rest or continue to move in a straight line at a constant speed unless acted upon by a resultant external force.
Define Newton’s Second law of Motion?
Force is the product of mass and acceleration.
Define Newton’s Third Law of Motion?
Every action has an equal and opposite reaction acting upon a different object.
Define Power?
The rate of work done (or the rate of energy transfer)
Define Efficiency?
Efficiency is the ratio of useful output power to total input power.
Define Moment of a Force?
Moment of a Force is the product of Force and the perpendicular distance between the force and the pivot.
Define the Principle of Moments?
The total clockwise moment is equal to the total anticlockwise moment about any point.
Define a Couple?
A Couple is a pair of equal and opposite forces that act on different points on the same object.
Define Torque?
Torque is the total moment of a couple, about any point
Define Current?
Current is the Rate of Change of Charge.
or the amount of charge flowing in one second
Define Potential Difference?
The work done per coulomb of positve charge.
Define Ohmic Conductor?
Ohmic conductors are those electrical conductors that follow Ohms law. In other words there is a linear relationship between voltage and current for all values.
Define Superconductor?
A material which below its critical temperature has ZERO resistance.
Define Semiconductor?
A material whose resistance decreases as temperature increases
Define Resistivity
Resistivity is a property that describes the extent to which a material opposes the flow of electric current through it
Define EMF?
Electromotive force
The potential difference of a supply when no current is being drawn.
Define Internal Resistance?
The electrical resisctance of a power supply.
Define Kirchoff’s First Law?
The algerbraic sum of the currents at at pount is equal to Zero.
(Or the total current flowing into a point is equal to the current flowing out of the point).
Define Kirchoff’s Second Law?
The algerbraic sum of the EMF is equal to teh sum of the potentail difference around aclosed loop.
(or total emf must be equal to pd across the components of a closed loop).
Define Period of a Wave?
The time taken for one complete oscillation.
Define Frequency of a Wave?
The number of oscillations in one second.
Define Path Difference?
The difference in distance travelled by two waves from their respective sources to a given point.
Define Phase Difference?
Phase Difference is used to describe the difference in degrees or radians when two or more alternating quantities reach their maximum or zero values.
Define Polarisation?
The action of restricting the vibrations of a transverse wave, especially light, wholly or partially to one direction.
Define Coherent Sources?
At leat on source of waves which have the same, frequencey and wave speed. And have a constant phase difference.
Define Stationary Waves?
Waves which are traveling at the same speed, in opposite directions and have the same frequency.
Define Antinode?
A point of constructive interference.
Define Node?
A point of destructive interference?
Define Work Function?
The minimum amount of energy a conduction electron must gain to leave the surface of the material.
Define Threshold Frequency?
The minimum frequency required to transfer enough energy to a conduction electron, for it to leave the surface of the material.
Define Stopping Potential?
Stopping potential is the minimum negative voltage applied to the anode to stop the photocurrent.
Define Isotopes?
Atoms which have the same number of protons by=ut z different number of neutrons.