Which statement about connecting a voltmeter to a DC circuit is true?

• A. The voltmeter leads orientation to negative/positive
• B. The polarity of the leads does not matter
• C. The polarity must be reversed for every measurement
• D. The voltmeter cannot be used with DC circuits

Answer: (A)

When measuring DC voltage, you’re reading a definite potential difference with a specific sign. A voltmeter has two terminals and is connected in parallel to the part of the circuit you’re testing. The reading’s sign depends on which terminal is on the higher-potential side: connect the positive terminal of the meter to the higher-potential node and you get a positive value; swap the leads and the same magnitude appears with a negative sign. So the orientation of the leads relative to the circuit’s polarity matters for interpreting the result.

The other statements aren’t correct: DC measurements are supported by voltmeters, and you don’t need to reverse the polarity for every measurement—only if you want to observe the opposite sign.