Capacitor behavior after disconnection If a charged capacitor is disconnected from its circuit and left isolated (ideal conditions), what happens to its stored charge?

Introduction / Context:
Knowing how capacitors behave when isolated is important for safety, troubleshooting, and the design of hold-up or sample-and-hold circuits. A capacitor can retain energy even after power is removed, which can be both useful and hazardous.

Given Data / Assumptions:

• Capacitor initially charged to some voltage V.
• After charging, it is completely disconnected (no resistive path).
• Ideal dielectric with infinite insulation resistance (for theory); real capacitors are discussed as practical note.

Concept / Approach:
Charge stored on a capacitor remains unless a discharge path exists. In an ideal case, with no conductive path across the terminals and perfect dielectric, the charge and voltage remain constant indefinitely. Real components slowly lose charge due to finite insulation resistance and dielectric absorption, but not immediately.

Step-by-Step Solution:
Disconnect the capacitor from any circuit so no closed path exists.With no path, current i = 0, so Q (stored charge) remains constant.Voltage V = Q / C therefore stays constant (ideal case).In practice, leakage resistance forms a very large RC time constant, so voltage decays slowly over time.

Verification / Alternative check:
Measuring the capacitor terminals with a high-impedance meter immediately after disconnection shows the retained voltage; the reading decays gradually depending on leakage and meter loading.

Why Other Options Are Wrong:
Immediately discharge: requires a conductive path; none exists after isolation.Recharge: there is no source present to increase voltage.Leak the charge instantly: leakage exists in reality but is slow, not instantaneous.

Common Pitfalls:
Touching terminals provides a discharge path; residual charge can be dangerous in high-voltage capacitors.Assuming measurement instruments do not affect charge; low-impedance meters can discharge the capacitor.

Final Answer:
Remain charged