Question

a 120 - v electrical line in a home is connected to a 100 - w lightbulb, a 180 - w television set, a 300 - w desktop computer, a 1050 - w toaster, and a 240 - w refrigerator. part a how much current is flowing in the line? express your answer to three significant figures and include the appropriate units.

Explanation:

Step1: Calculate total power

The total power $P_{total}$ of all the appliances is the sum of their individual powers.
$P_{total}=100 + 180+300 + 1050+240=1870\ W$

Step2: Use power - voltage - current relation

The power formula is $P = VI$, where $P$ is power, $V$ is voltage and $I$ is current. We want to find $I$, and we know $P = P_{total}$ and $V = 120\ V$. Rearranging for $I$ gives $I=\frac{P}{V}$.
$I=\frac{1870}{120}\ A\approx 15.6\ A$

Answer:

$I = 15.6\ A$