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42 Cards in this Set
 Front
 Back
Current 
The Rate of flow of Charge 

1 coulomb 
Amount of charge that passes in 1 second when current is 1 ampere. 

Potential Difference 
Work done per unit of charge 

Mean Drift Velocity 
Average velocity of the charge carriers 

Resistance 
Property of a component that regulates the electric current through it. 

3 Things that affect resistance 
Length Area Resistivity 

how does length affect the resistance of a wire? 
The longer the wire, the more difficult it is to make a current flow through it. 

How does area affect resistance? 
The bigger the area, the lower theresistance 

Restivity 
Ratio of the product of resistance and cross sectional area of a component to its length 

Ohms Law 
Current is directly proportional to the potential difference provided temperature stays constant. 

Name the component 
Metallic conductor 

Name the component 
Filament Lamp 

Thermistor 
Resistor with a resistance that depends on temperature. 

Negative Coefficient Thermistor 
Resistance decreases as temperature increases. 

Resistance of LDR 
the greater the light intensity the lower, the lower the resistance. 

Diodes 
Only let current flow in one direction (forward bias). resistance is very high in the reverse bias. 

Name the component 
Diode 

Power 
Rate of transfer of energy 

Kilowatt hour 
3,600,000 Joules 

E.m.f 
Total work done by a battery on each coulomb of charge 

Internal resistance 
Resistance to an electric current of the materials inside. 

Kirchoff's first law 
Total current entering a junction is equal to the total current leaving it. 

Kirchoff's second law 
Total emf around a series circuit is equal to the sum of the p.d's across each component. 

Potential divider 
Circuit using two resistors in series to split or divide up the p.d in proportion to the resistance of the components. 

Potentiometer 
A variable resistor 

What is the photoelectric effect?

Emission of electrons from the surface of a material when electromagnetic radiation is incident on it.


electronvolt 
kinetic energy gained by an electron when it is accelerated through a potential difference of 1 volt.


Threshold frequency

minimum frequency of radiation to ionise an electron from a metal surface.


quantum

Small discrete unit of energy.


photon

quantum associated with electromagnetic energy


explain relation between intensity and photoelectron emission.

number of photoelectrons emitted is directly proportional to the intensity of the radiation. provided its frequency is equal to or above the threshold frequency of the metal.


wave particle duality

The theory that all objects can exhibit wave and particle properties.


De Broglie's wavelength 
Equation expressing the wavelength of a particle as a ratio of Planck's constant and particle momentum


work function 
minimum energy required to release an electron from its surface, overcoming the electrostatic attraction between the electron and the positive metal ion.


moments

the turning effect of a force


the principle of moments

for an object to be in equilibrium, the sum of the clockwise moments must be equal to the sum of the anticlockwise moments.


torque 
the turning effect produced by a couple


pressure

force per unit area 

Archimedes' priniciple

when a body is completely or partially submerged in fluid. it experiences an upthrust equal to the weight of the object. 

what causes upthrust?

caused by the top and bottom of a body being at different depths.


power

work done per second


density

mass per unit volume 