Physics
When the main switch of the house is put off it disconnects the

Live wire and the neutral wire
Earth wire and the neutral wire
Live wire only
Live wire and the earth wire

ANSWER DOWNLOAD EXAMIANS APP

Physics
In a railway track, two rails are joined end to end with a gap in between them because

Accidents due to contraction in winter can be avoided
Steel can be saved
Accidents due to expansion in summer can be avoided
Air-gaps are necessary for bearing the weight of running train

ANSWER DOWNLOAD EXAMIANS APP