Four identical resistors have 12 ohm each. find the equivalent resistance req when : (a) all four of them are connected in series, and (b) when all four are connected in parallel.

(a): When the four resistors are connected in series the equivalent resistor value is Req= 48Ω

(b): when the four resistors are connected in parallel the equivalent resistor value is Req=3Ω

Explanation:

R=R1=R2=R3=R4= 12Ω

(a)

Req= R1+R2+R3+R4

Req= 48 Ω

(b)

Req= (1/12 * 4)⁻¹

Req= 3 Ω