Question

A 5 ohm resistor is connected in series with a parallel combination of n resistors each of 6 ohm. the equivalent resistance is 7 ohm. find n

Answer 1

answer=12

Resistance in parallel= 1= 1 +1 .....+1

R R1 R2 Rn

1 = 1 + 1 .....+1

R 6 6 6

1 = n

R 6

total resistance= 5 + n

6

7= 5+n

6

7= 30+n

6

42= 30+n

42-30=n

12=n