Question

How many resistors of 160 Ω should be connected in parallel to get 11 A current from a 220 V supply?

• A.
  3
• B.
  6
• C.
  4
• D.
  8

Answer 1

The correct option is D

8
Let n resistors are connected in parallel
We know that,
$\frac{1}{R_E}=\frac{1}{R^{}}+\frac{1}{R^{}}+\frac{1}{R^{}}------nterms\frac{1}{R_E}=\frac{n}{R}{R}_E=\frac{R}{n}$Given, R = 160 Ω ; I = 11 A ; V = 220 V

$R_E=\frac{160}{n}$
By ohm's law,
$V=I{R}_E$
$220=11\times \frac{160}{n}$
$20n=160$
$n=8$
Thus, 8 resistors are connected in parallel.