Which of the following precautions should be taken when measuring in-circuit resistance with an ohmmeter?
Ensure that the applied voltages are correct
Ensure that the circuit is not powered✓Правильный ответ
Ensure that the circuit is grounded
Ensure that the circuit is operating at the correct frequency
Объяснение
An ohmmeter works by supplying its own current, so any voltage present in the circuit adds to or opposes that current and makes the reading meaningless, besides risking damage to the meter. Removing power first is therefore the required precaution.