Resistance of a Headlight

What is the resistance of an automobile headlight through which 2.50 A flows when 12.0 V is applied to it?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Strategy
Ohm’s law tells us $V_{headlight} = I R_{headlight}$ . The voltage drop in going through the headlight is just the voltage rise supplied by the battery, $V_{headlight} = V_{battery}$ . We can use this equation and rearrange Ohm’s law to find the resistance $R_{headlight}$ of the headlight.
Solution
Solving Ohm’s law for the resistance of the headlight gives

$\begin{matrix} V_{headlight} & = & I R_{headlight} \\ V_{battery} & = & I R_{headlight} \\ R_{headlight} & = & \frac{V_{battery}}{I} = \frac{12 V}{2.5 A} = 4.8 Ω. \end{matrix}$
19.6

0 of 2 steps open

How did it go?