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
The unit of self inductance is
henry
weber/m2
siemens
ampere-turn per weber
Magnetic lines of force
are mere directions
have no physical reality
can be used to indicate the direction of the magnetic of the magnetic field of a point
all the above are correct
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
The most suitable material for making the core of an electromagnet is :
soft iron
brass
aluminium
steel
The north-south polarities of an electromagnet can be found easily by using :
Fleming's right-hand rule
Fleming's left-hand rule
Clock face rule
Left-hand thumb rule
Magnetic effect of electric current was discovered by
Max well
Oersted
Ampere
Fleming
At what voltage is the electric power generated at the power generating station?
11 kV
25 kV
21 kV
40 kV
The frequency of AC used in India is
50 Hz
100 Hz
200 Hz
1/100 Hz
A d.c. generator is based on the principle of :
electrochemical induction
electromagnetic induction
