If the charge on a capacitor is doubled, what happens to the energy stored in it

Practice Questions

Q1
If the charge on a capacitor is doubled, what happens to the energy stored in it?
  1. It doubles
  2. It quadruples
  3. It remains the same
  4. It halves

Questions & Step-by-Step Solutions

If the charge on a capacitor is doubled, what happens to the energy stored in it?
  • Step 1: Understand that a capacitor stores energy based on its charge and voltage.
  • Step 2: Know the formula for energy stored in a capacitor: U = 1/2 * C * V^2, where U is energy, C is capacitance, and V is voltage.
  • Step 3: Recognize that charge (Q) on a capacitor is related to voltage (V) by the formula Q = C * V.
  • Step 4: If the charge (Q) is doubled, then Q' = 2Q.
  • Step 5: Since Q = C * V, if Q is doubled, the new voltage (V') will also change. We can express the new voltage as V' = Q' / C = (2Q) / C = 2V.
  • Step 6: Substitute the new voltage (V') into the energy formula: U' = 1/2 * C * (2V)^2.
  • Step 7: Calculate (2V)^2, which equals 4V^2.
  • Step 8: Now substitute this back into the energy formula: U' = 1/2 * C * 4V^2.
  • Step 9: Simplify the equation: U' = 2 * (1/2 * C * V^2) = 2U.
  • Step 10: Conclude that if the charge is doubled, the energy stored in the capacitor quadruples.
  • Capacitor Energy Storage – The energy stored in a capacitor is related to its capacitance and the voltage across it, specifically U = 1/2 * C * V^2.
  • Charge and Voltage Relationship – Doubling the charge on a capacitor affects the voltage, which in turn affects the energy stored.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely