Question

how many resistors with resistance of 176 ohms should be connected in parallel so that their combination draws a current of 5 amp from 220 volt supply line?

Answer 1

For Resistors in Parallel,

1/R(total) = 1/R₁ + 1/R₂ + 1/Rₓ

From Ohm's Law 

V = IR

220 = (5)R

R = 44 Ω

Therefore

1/44 = No. of 176Ω Resistors * 1/176

Let no. of 176Ω Resistors be x

Then 1/44 = x/176

x = 4

Therefore, 4 resistors of 176Ω ( in parallel) are required to carry 5 A on a 220 V line.

Answer 2

R=176

I=5A

V=220V

R=R1+R2

V=I×R

220=5×176=880-220=660