एक मूविंग-कॉइल गैल्वेनोमीटर मुख्य रूप से किस सिद्धांत पर कार्य करता है?

When two alternators are synchronized using a moving-iron synchroscope, on what does the speed and direction of rotation of the synchroscope pointer depend?

Which of the following instruments is primarily used to measure high insulation resistance?