A switch is always connected to the
earth wire
neutral wire
live wire
none of these
The frequency of AC used in India is
50 Hz
100 Hz
200 Hz
1/100 Hz
According to International convention of colour coding of insulation of wires in a cable :
live is red, neutral is blue and earth is brown
live is red, neutral is green and earth is black
live is brown, neutral is blue and earth is black
live is brown, neutral is light blue and earth is green
An electric motor is a device which transforms :
mechanical energy to electrical energy
heat energy to electrical energy
electrical energy to heat energy only
electrical energy to mechanical energy
Circuit Breaker Device which can be used in place of fuse wire in domestic electric wiring is called :
CBD
DCB
MCD
MCB
An MCB which cuts off the electricity supply in case of short-circuiting or overloading works on the :
chemical effect of current
heating effect of current
magnetic effect of current
electroplating effect of current
At what voltage is the electric power generated at the power generating station?
11 kV
25 kV
21 kV
40 kV
The most suitable material for making the core of an electromagnet is :
soft iron
brass
aluminium
steel
A d.c. generator is based on the principle of :
electrochemical induction
electromagnetic induction
At the time of short circuit, the current in the circuit :
reduces substantially
does not change
increases heavily
varies continuously
