Question

Shows a 240 V a.c. mains circuit to which a number of appliances are connected and switched on.
(a) calculate the power supplied to the circuit.

• A. $1620.19W$
• B. $1520.19W$
• C. $1720.19W$
• D. $1820.19W$

Answer 1

The correct option is B $1520.19W$

Fan ---- $R_f=\frac{v^2}{P}=\frac{{240}^2}{1200}$

$=48$

Refrigerator---- $R_r=\frac{{240}^2}{200}=288\Omega$

$R_B=\frac{{240}^2}{60}=960$

$\frac{1}{R_{eq}}=\frac{1}{48}+\frac{1}{288}+\frac{1}{960}$

$R_{eq}=37.8\Omega$

Power $=\frac{{240}^2}{37.89}=1520.19W$