Physics
Out of the two given cases of wiring of a house, which one is relatively safer ?
(a) House A ⟶ Switch in neutral with earth connected.
(b) House B ⟶ Switch in live with no earth connected.
- Both are equally safe.
- Both are equally unsafe.
- House B is safer.
- House A is safer.
Answer
House B is safer.
Reason — A switch must always be connected in the live wire so that switching it off completely disconnects the appliance from the supply.
In House A, the switch is in the neutral wire, so the appliance remains connected to the live wire even when switched off, which is unsafe. Although earthing is important, proper placement of the switch in the live wire is more critical for preventing electric shock in this case.
Hence, House B is relatively safer than House A.
Related Questions
The use of MCB is more convenient than a fuse because :
- it avoids the inconvenience of connecting a new fuse wire
- it is much safer for quick response
- it takes a very long time for tripping
- both (1) and (2)
A switch in a table lamp is connected in the neutral wire. The lamp works fine. Identify the correct statement :
- Current flow stops when switch is off, it is safe.
- It is safe because neutral wire is at zero potential.
- It is unsafe as switch gets heated.
- It is unsafe as lamp body is connected to the live wire.
Assertion (A): A fuse wire must have a high resistance and low melting point.
Reason (R): A fuse is only used for a small current flow.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.
Assertion (A): Same current flows through the live wires and the filament of a bulb, but the heat produced in the filament is much higher.
Reason (R): The filament of a bulb is made of low resistance and high melting point.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true and R is not the correct explanation of A.
- assertion is false but reason is true.
- assertion is true but reason is false.