Question

How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?

Answer 1

For x number of resistors of resistance 176 Ω, the equivalent resistance of the resistors connected in parallel is given by Ohm's law as $V= IR$
$R= \frac VI$
Where,
Supply voltage, $V= 220 \ V$
Current, $I = 5\ A$
Equivalent resistance of the combination = $R$, given as
$\frac 1R = x \times (\frac {1}{176})$

$R = \frac {176}{x}$
From Ohm's law,
$\frac VI = \frac {176}{x}$
$x = 176 \times \frac IV$

$x= 176 \times \frac {5}{220}$
$x= 4$

Therefore, four resistors of 176 Ω are required to draw the given amount of current.