6 V
12 V
40 V
100 V
Answer is Wrong!
Answer is Right!
The correct answer is D. 100 V.
A megger is a high-voltage insulation tester. It is used to test the insulation resistance of electrical equipment and wiring. The operating voltage of a megger is typically 100 V, but it can vary depending on the model of the megger.
Option A is incorrect because 6 V is too low a voltage to test the insulation resistance of most electrical equipment. Option B is incorrect because 12 V is also too low a voltage for most applications. Option C is incorrect because 40 V is a common voltage for some meggars, but it is not the most common voltage.
Therefore, the correct answer is D. 100 V.