Question 546Electricity & Electronics - Assistant Engineer

The correct answer is B) 'ghost' voltages due to electromagnetic energy in the air. When a digital multimeter is set to measure AC volts and its leads are disconnected, it may still display a small non-zero reading. This is due to the meter's sensitivity to electromagnetic fields in the surrounding environment, which can induce small 'ghost' voltages in the meter's circuitry. This is a normal and expected behavior, and does not indicate a problem with the meter's calibration or grounding. The other options are incorrect as they do not accurately explain this phenomenon.