Multiple choice

The instrument used to change the direction of flowing of current in dynamo is

  1. voltmeter

  2. ammeter

  3. commutator

  4. key

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A commutator is a rotary switch in a dynamo/generator that reverses the current direction periodically, converting AC to DC in the external circuit. Voltmeters measure voltage, ammeters measure current, and keys are switches - none change current direction.