Question

How many 176 $\Omega$?resistor(in parallel) are required to carry $5A$ in $220V$ line.

Answer 1

For $x$ number of resistors of resistance $=176$

$V=220V$

$I=5A$

$\therefore$ Equivalent resistance of the combination $R$ given as

$=\frac{1}{R}=x\left(\frac{1}{176}\right)\Rightarrow R=\frac{176}{x}$

From ohms law

$\frac{V}{I}=\frac{176}{x}$

$\Rightarrow$ $x=\frac{170\times I}{V}$

$=\frac{170\times 5}{20}=4$

$\therefore$ $x=4$