Physics - EMI/AC Question with Solution | TestHub
A non-conducting cylindrical rod is inserted within two coils of insulated wires, as shown in the given figure. A battery is connected to coil, while a galvanometer is connected to coil
On switching on the current in coil,
Options:
Answer:
Solution:
On closing the switch, current begins flowing through coil 1. Hence, a magnetic field will be produced in this coil. The magnetic field varies from zero to a maximum value in a certain time. As a result, the field across coil 2 will change for that time. This change in field will cause current to be induced in coil 2 for that short time. This phenomenon of generation of current in coil 2, caused by the variation in the magnetic field of coil 1, is known as electromagnetic induction. The current induced in coil 2 will deflect the pointer of the galvanometer connected to it.
Why alternative A is wrong:
Coil 2 will not move toward coil 1 because no mechanical force is produced on closing the switch.
Why alternative B is wrong:
Coil 2 will not move away from coil 1 because there is no mechanical force that could repel it.
Why alternative C is wrong:
Since current will be induced in coil 2, the pointer of the galvanometer will not remain at zero.
The correct answer is D.
