Diode Rectification for Battery Charging

Steps:

• AC supply produces alternating current, positive and negative half-cycles.
• Diode conducts only during the positive half-cycle relative to its orientation.
• This allows unidirectional current to flow into the battery, reversing the discharge direction.
• Negative half-cycle is blocked, preventing damage and enabling net charging.

Why A is correct:

• Circuit A orients the diode to conduct during the AC half-cycle that matches the battery's charging polarity, per diode's one-way conduction law.

Why the others are wrong:

• B: Diode reversed, blocks charging current entirely.
• C: Diode in parallel, bypasses battery without rectification.
• D: No diode, full AC damages battery via bidirectional flow.

Final answer: A