Questions on electricity usually take the form of simple circuit diagrams.
These diagrams are usually restricted to showing the power source, switches, loads (typically bulbs), and the path of the wiring. To answer these questions you need a basic understanding of how electricity flows around a circuit.
Example Question
1. How many switches need to be closed to light up one bulb?
2. How many bulbs will light up when the switch is closed?
3. If bulb 1 is removed, how many bulbs will light up when the switch is closed?
Answer to Question
1. B – Two switches need to be closed to complete a circuit.
2. D – All 4 bulbs will light up.
3. B – Only bulbs 2 and 4 will light up.