Question

What is the total power of three 10 ohm bulbs when they are connected in a 12 volt series circuit?

Answer 1

4.8 watts

Explanation

the total power can be found by using the formula

$\begin{gathered} P=\frac{V^2}{R} \\ where\text{ P is the power} \\ V\text{ is the voltage} \\ R\text{ is the resistance} \end{gathered}$

so

Step 1

find the total resisitance:

if the bulbs are conected in serie ,then

$\begin{gathered} R_{eq}=R_1+R_2+R_3 \\ R_{eq}=10\text{ ohms+10 ohms+10ohmns} \\ R_{eq}=30\text{ ohms} \end{gathered}$

now, replace in the formula

$\begin{gathered} P=\frac{V^{2}}{R} \\ P=\frac{(12\text{ V\rparen}^2}{30\text{ ohms }} \\ P=4.8\text{ watts} \end{gathered}$

therefore, the answer is

4.8 watts

I hope this helps you