1.
The unit of induced emf is
2.
The fact that current is associated with a magnetic field was discovered by
3.
By increasing the number of turns in the coil, the strength of the magnetic field
4.
Choose the correct statement:
6.
The coil of a heater is cut into two equal halves and only one of them is used in the beater. The ratio of the heat produced by this half of the col to that produced by the original coil is
8.
A compass needle just above a wire in which electrons are moving towards east, will point
9.
A magnetic field cannot exert any force on a
10.
A magnetic field can exert force on a
11.
It is a common notion that the earth's magnetism is due to the
12.
The unit of magnetic flux is
13.
By inserting a soft iron piece into a solenoid, the strength of the magnetic field
14.
Fleming's right hand rule gives
15.
The resistance of a conductor is reduced to half its initial value. In doing so the heating effects in the conductor will become
16.
Ampere rule is used to find the
17.
An electric iron draws a current of 4 A when connected to a 220 V mains. Its resistance must be
18.
If current in the core decreases, the strength of the magnetic field
19.
The force between two parallel wires carrying currents has been used to define
20.
The force of repulsion between two parallel wires is f when each one of them carries a certain current /. If the current in each is doubled, the force between them would be
