Terminal potential difference decreases with increasing current

Steps:

• Light intensity on LDR increases, decreasing its resistance.
• Total circuit resistance decreases, increasing current through the cell.
• Voltmeter, likely across fixed resistor, shows higher reading due to increased current.
• Higher current causes greater voltage drop across internal resistance.

Why D is correct:

• Terminal potential difference $V = E - Ir$, where increased $I$ reduces $V$ due to larger internal drop.

Why the others are wrong:

• A: Current (charge per unit time) increases as total resistance falls.
• B: Energy per unit charge is emf $E$, which remains constant.
• C: Light intensity increases to lower LDR resistance and raise voltmeter reading.

Final answer: D