ordinary moving coil galvanometer cant be used to measure AC
Answers
Explanation:
Galvanometer is an electromechanical instrument which is used for the detection of electric currents through electric circuits. Being a sensitive instrument, Galvanometer can not be used for the measurement of heavy currents. However we can measure very small currents by using galvanometer but the primary purpose of galvanometer is the detection of electric current not the measurement of current.
The average value for AC is zero because that's how it's produced in an alternator because the machine is symmetrical with the rotor rotating in a magnetic field. I'm not even sure if it would be possible to make a non-zero average just with a misaligned alternator.
You could make AC with a DC offset easily enough with an electronic inverter, but the DC component would just heat up transformers without doing anything useful like transferring power to the secondary, so it would be pointless.