Safety Isolation in Electrical Circuits

Steps:

• Identify the live wire as the one carrying current from the supply to the load.
• Recognize that switching the live wire disconnects the supply voltage to the lamp.
• Understand that this isolates the lamp, preventing current flow even if faults occur.
• Confirm this setup ensures user safety by avoiding live components when off.

Why A is correct:

• Placing the switch in the live wire isolates the lamp from the power supply, adhering to electrical safety standards that require disconnecting the hot line to prevent shock hazards.

Why the others are wrong:

• B: Fuses are placed in the live wire, not neutral, to protect against overloads.
• C: Switches function in either wire but are placed in live for safety isolation.
• D: Earth wire carries minimal current under normal conditions; it's for fault protection.

Final answer: A