Closing switch reduces equivalent resistance of load

Steps:

• With S open, current flows through one resistor only, so equivalent resistance is higher.
• Closing S adds a parallel resistor, lowering the total equivalent resistance of the load.
• Lower load resistance draws more total current from the battery, increasing ammeter reading (total current).
• Higher total current causes greater voltage drop across internal resistance, decreasing terminal voltage (voltmeter reading across load).

Why A is correct:

• Adding parallel path decreases load resistance per Ohm's law (V=IR), increasing current and internal voltage drop (V_terminal = E - Ir).

Why the others are wrong:

• B: Voltage decreases, not increases, due to internal drop.
• C: Ammeter reading increases with lower resistance.
• D: Voltmeter reading decreases from higher current through internal r.

Final answer: A