Internal Resistance Reduces Current and Terminal Voltage

Steps:

• Emf ε remains constant; total resistance is R + r.
• Current I = ε / (R + r); increasing r raises total resistance, so I decreases.
• Terminal pd V = I R (voltage across external resistor); decreasing I with constant R means V decreases.

Why A is correct:

• Ohm's law states V = I R; as r increases, I falls, causing V to decrease alongside I.

Why the others are wrong:

• B: I decreases, not increases, due to higher total resistance.
• C: V decreases with I, not increases.
• D: Neither V nor I increases; both drop.

Final answer: A