what is the difference between ammeter and voltmeter.
An ammeter is an electrical device used to measure current through a component in a circuit or current through a circuit. A voltmeter is an electrical device used to measure the voltage difference across any two points in a circuit.
In an ammeter a very low resistance is connected parallel to the coil the produces angular displacement in magnetic field when current flows through it. In a voltmeter a very high resistance is connected in series with the coil.
An ammeter is always connected in series with an external circuit. A voltmeter is always connected in parallel with an external circuit.