College

A [tex]$25 \mu F$[/tex] capacitor is connected to a 12-volt battery. How much energy can be stored in the capacitor?

([tex]$1 F = 10^6 \mu F$[/tex])

A. 1800 J
B. 0.00015 J
C. 0.0018 J
D. 150 J

Answer :

To determine how much energy can be stored in a capacitor, we use the formula:

[tex]\[ E = \frac{1}{2} C V^2 \][/tex]

where:
- [tex]\( E \)[/tex] is the energy stored in the capacitor (in joules),
- [tex]\( C \)[/tex] is the capacitance (in farads),
- [tex]\( V \)[/tex] is the voltage across the capacitor (in volts).

Let's solve the problem step-by-step:

1. Convert the Capacitance:
- The capacitance given is 25 microfarads ([tex]\( \mu F \)[/tex]).
- To convert microfarads to farads, use the conversion factor [tex]\( 1 F = 10^6 \mu F \)[/tex].
- So, [tex]\( 25 \mu F = 25 \times 10^{-6} F = 0.000025 F \)[/tex].

2. Input the Voltage:
- The voltage applied to the capacitor is 12 volts.

3. Calculate the Energy:
- Substitute the values into the energy formula:
[tex]\[
E = \frac{1}{2} \times 0.000025 \, F \times (12 \, V)^2
\][/tex]

- Simplifying the equation:
[tex]\[
E = \frac{1}{2} \times 0.000025 \times 144
\][/tex]

- Calculate the product:
[tex]\[
E = 0.0000125 \times 144 = 0.0018 \, \text{J}
\][/tex]

The energy stored in the capacitor is [tex]\( 0.0018 \, \text{J} \)[/tex]. Therefore, the correct answer is [tex]\( 0.0018 \, \text{J} \)[/tex].