If a 10F capacitor is to have an energy content of 20J, it must be placed across a potential difference of
Correct answer: B. 2 volts
- A. 4 volts
- B. 2 volts
- C. 9 volts
- D. 1 volt
Explanation
The energy stored in a capacitor is given by the formula E = 0.5 * C * V^2 where E is the energy in joules, C is the capacitance in farads, and V is the voltage in volts. For a 10F capacitor with an energy content of 20J, the equation becomes:20 = 0.5 * 10 * V^2Solving for V, we get:20 = 5 * V^2V^2 = 4V = 2 voltsTherefore, the correct answer is 2 volts. The other options result in incorrect energy calculations when substituted into the equation.
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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