Name the device (a) which creates potential difference in circuits. (b) conducting link between cell and bulb. (c) change the resistance in the ciruit without changing source (battery). (d) used to measure current in circuit. (e) used to measure potential difference.

Answer:a) In a circuit, an electric field is created. This electric field forces electrons to move ... A potential difference in a circuit merely means that work is done on electrons by an electric field as they pass through the circuit and their potential energy changes. b) When the two ends of a cell are connected to a bulb using metal wires, the bulb emits light. The bulb glows due to flow of electric current from the positive terminal to the negative terminal through the filament of the bulb. Such a circuit is called a closed circuit.