The diagram below shows the direction of flow of current marked by red arrows and the labelled parts — A, B, C, D, E, and F
| Part | Function |
| Ammeter | An ammeter is an instrument used to measure the magnitude of current flowing in a circuit. |
| Cell | It acts as a source of direct current for the circuit. |
| key | It is used to put the current on and off in the circuit. |
| Load | An appliance which is connected in a circuit. |
| Voltmeter | A voltmeter is used to measure the potential difference between two points of a circuit. |
| Rheostat | A rheostat is a device by which resistance in a circuit can be varied continuously. |
