1.
The unit of induced emf is
2.
If current in the core decreases, the strength of the magnetic field
3.
A magnetic field cannot exert any force on a
4.
A compass needle just above a wire in which electrons are moving towards east, will point
5.
The force between two parallel wires carrying currents has been used to define
6.
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
7.
The fact that current is associated with a magnetic field was discovered by
8.
Choose the correct statement:
10.
By inserting a soft iron piece into a solenoid, the strength of the magnetic field
11.
By increasing the number of turns in the coil, the strength of the magnetic field
12.
The unit of magnetic flux is
13.
Ampere rule is used to find the
15.
Fleming's right hand rule gives
16.
It is a common notion that the earth's magnetism is due to the
17.
The resistance of a conductor is reduced to half its initial value. In doing so the heating effects in the conductor will become
18.
An electric iron draws a current of 4 A when connected to a 220 V mains. Its resistance must be
19.
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
20.
A magnetic field can exert force on a
