The electric current I (in amperes) of an electric circuit varies directly as the voltage V. When 24 V is applied, the current is 8 amperes. Find the current when 12 V is applied. I =

Answer 1

Ohms Law is V=IR or I = V/R

24 = 8R 8 = 24/R

12 = 4R 4 = 12/R

I = 4 amperes when V = 12 volts

if I = 8 when V= 24

R = resistance = a constant independent of the current

R=V/I = 24/8 = 12/4 = 3 ohms