Question

Three resistors of values 1ohm 3ohm and 6ohm are connected in parallel to a dry cell .
Find total effective resistance of the three resistors

Answer 1

1/R=9/6

R=6/9

=2/3

=0.66666667

Answer 2

let the three resistors be R1 = 1 ohm, R2 = 3 ohm and R3 = 6 ohm

R = total resistance of the three resistors

.°. 1/R = 1/R1 + 1/R2 + 1/R3

=> 1/R = (R2R3 + R3R1 + R1R2) / R1R2R3

=> 1/R = (3×6 + 6×1 + 1×3) / 1×3×6

=> 1/R = (18 + 6 + 3) / 18

=> 1/R = 27/18

=> 1/R = 3/2

=> R = 2/3

=> R = 0.67 ohm

Hope it'll help..