Heating Effect of an Electric Current (Leaving Cert Physics): Flashcards

Heat energy produced when current flows through resistance

Electrons collide with atoms, transfer kinetic energy

$W = I^2Rt$

$W propto I^2$ (proportional to current squared)

Produces four times as much heat

Rate at which energy is converted or transferred

$P = I^2R$

$P = VI$

P = rac{V^2}{R}

Linear I-V relationship, constant resistance

Non-linear I-V relationship, resistance changes with temp

Resistance increases as temperature rises

Resistance decreases as temperature increases

rac{ ext{useful output power}}{ ext{input power}} imes 100%