Two opposite-connected sources of equal magnitude in series: net voltage is

• A. Zero
• B. Twice the magnitude
• C. The difference between the voltages
• D. Equal to the larger source

Answer: (A)

In a series arrangement, voltages add with their signs. If two sources are connected opposite to each other, their voltage rises oppose one another. When their magnitudes are equal, these opposing rises cancel out exactly, so the algebraic sum of the emfs is zero. That means there’s no net electromotive force across the ends of the pair, and a voltmeter would read zero volts (assuming ideal sources).

If the connections weren’t opposite, you’d see different outcomes: same direction would give a larger net voltage (twice the magnitude in this equal case), while unequal magnitudes would yield the difference between them. But with equal magnitudes and opposite orientation, they cancel, giving zero.