Alternating current cannot be measured by a DC ammeter because

A resistance R is connected to a cell of EMF E and has an internal resistance r as shown in the figure. The voltage across R is measured using and ideal A voltmeter and circuit current is measured by an ammeter. A rheostat of negligible resistance is used to vary the current in the circuit. -Write down the expression for current in the circuit and voltage across R at any instant.

Alternating current is produced by AC generator.If the frequency of rotation of electromagnet In a generator Is Increased, the voltage.