Topic 5

Coulomb's law

Like charges repel each other; unlike charges attract.

electric field

a region of space where a small positive test charge experiences a force due to its charge

electric field strength

force per unit charge experienced by a positive test charge placed in the field

Moving charge

 the amount of charge that passes a fixed point in a given period of time

current

flow of electric charge

potential difference

the work done by moving a positive test charge from one point to another in an electric field

electron-volt

the energy required to accelerate an electron across a potential difference of 1 volt

Internal resistance

Resistance of the cell. As current flows through internal resistance, some energy is converted from electrical to heat inside the cell.

resistance

Rate at which charge can flow through a conductor

emf

Amount of chemical energy converted to electrical energy, per unit charge.

ohmic and non ohmic behavior

Ohmic conductor obeys the Ohm's Law (V=IR), which means that the potential difference is proportional to current. Non-ohmic conductor doesn't obey Ohm's Law.

parallel resistors

1/r = 1/r1 + 1/r2

in series resistors

r = r1 +r2

voltmeter connected in

parallel

ammeter connected in

series

secondary cell

can be recharged after use by passing current through the circuit in opposite direction to the current during discharge