Question

Your car's 30.0 W headlight and 2.50 kW starter are ordinarily connected in parallel in a 12.0 V system. What power (in W) would one headlight and the starter consume if connected in series to a 12.0 V battery

Answer 1

Answer:

The power of headlight in series connection is 29.64 W

Explanation:

Given :

Power of headlight $P_{1} = 30$ W

Power of starter $P_{2} = 2500$ W

Voltage of headlight and starter $V = 12$ V

From equation of power,

 $P = \frac{V^{2} }{R}$

 $R = \frac{V^{2} }{P}$

For finding the resistance of headlight and starter,

⇒ For headlight,

 $R_{1} = \frac{144}{30} = 4.8$ Ω

⇒ For starter,

$R_{2} = \frac{144}{2500} = 0.057$ Ω

Since equivalent resistance,

$R_{eq} = R_{1} + R_{2} + ........$

$R_{eq} = 4.8 +0.057 = 4.857$ Ω

So power in series is given by,

 $P_{s } = \frac{V^{2} }{R_{eq} } = \frac{144}{4.857}$

 $P_{s } = 29.64$ W