Two bar magnets A and B are released simultaneously from the same height with th
ID: 1271708 • Letter: T
Question
- Two bar magnets A and B are released simultaneously from the same height with their south poles pointing toward the ground. Magnet A is simply dropped through the air, while magnet B passes through a coil of wire with many turns during its fall.
Which of the following statements are true? (Give ALL correct answers, i.e., B, AC, BCD...)
A) An induced current in the wire coiled wire creates no additional magnetic field.
B) The induced current flips direction as magnet B falls through the wire.
C) Magnet B induces a current in the coiled wire as it falls through it.
D) Magnet A does not create any electric field as it falls.
E) The bar magnets reach the ground at the same time.
F) Magnet B creates a circling electric field as it falls.
Explanation / Answer
We know that a moving magnet always creates a electric field.
Magnet A does not create any magnetic field while falling as it is not passing through any kind of current carrying coils.
On the other hand magnet B passes through coil of wire on which it induces current due to ampere's circuital law.
the direction of induced current by lenz 's law is such that it opposes the direction of falling of the magnet. Thus the induced current creates magnetic field to oppose movement of magnet B and deccelerates it.Thus A,D and E are false options
from above discussion it is clear that C and F are correct options .B is also correct as direction of induced current reverses as soon as north pole of magnet passes through the coil