Kirchhoff's Voltage Law for series circuits

Steps:

• In a series connection, the same current flows through all resistors and the battery.
• The battery supplies emf E, which drives the current I = E / R_total, where R_total is the sum of resistances.
• Potential difference across each resistor is V_i = I * R_i.
• The total potential difference equals E: sum V_i = I * sum R_i = E.

Why D is correct:

• Kirchhoff's voltage law states that the directed sum of potential differences in a closed loop is zero, so the battery emf equals the sum of potential drops across the resistors.

Why the others are wrong:

• A: Resistors experience potential differences (not emfs), and each V_i depends on its resistance, not equaling the full battery potential difference.
• B: Resistors produce no emf (only voltage drops); emf is solely from the battery.
• C: Identical to D in meaning, but D provides the concise, precise wording matching the question's terminology.

Final answer: D