[Case: In our homes we receive electric power through mains (overhead poles or underground cables); the potential difference between the live wire and neutral wire of this supply is 220 V.] Write the colours of the insulation covers of the line wires through which supply comes to our homes.
Domestic electric circuits
Usually 2 marks a paper · mostly case-based questions and MCQs · asked in 2 of the last papers
Notes are being written
The board questions below are real and complete — they come from the CBSE papers themselves. The written notes for this topic are still being prepared.
Board questions on this topic
4 from the CBSE papers we hold — the exact wording the board used.
[Case: Domestic mains supply at 220 V between live and neutral wires.] What is the function of the earth wire ? State the advantage of the earth wire in domestic electric appliances such as electric iron.
[Case: Domestic mains supply at 220 V between live and neutral wires.] List two precautions to be taken to avoid electrical accidents. State how these precautions prevent possible damage to the circuit/appliance.
In domestic electric circuits the wiring with 15 A current rating is for the electric devices which have
- (a) higher power ratings such as geyser.
- (b) lower power ratings such as fan.
- (c) metallic bodies and low power ratings.
- (d) non-metallic bodies and low power ratings.