10. Current of Electricity

Definition and equations:
Electric current: flow of charged particles.
Charge at a point. product of the current at that point and the time for which the current flows,Q=It
Coulomb: charge flowing per second pass a point at which the current is one ampere
Charge is quantized: values of charge are not continuous they are discrete
All charges are multiples of charge of 1e: 1.6x10^-19C
Potential Difference: two points are a potential difference of 1V if the work required to move 1C of charge between them is 1 joule
Volt: joule per coulombW=VQ

Current-Carrying Conductors

Electrons move in a certain direction when p.d. is applied across a conductor causing current.

Current-P.D. Relationships

R = \frac{\text{ρL}}{A}