Physics - Magnetism Question with Solution | TestHub
Choose the WRONG Statement from the following statements.
(A) A toroid is a solenoid bent in the form of a closed ring.
(B) The magnetic field lines of solenoid are straight lines parallel to the axis inside the solenoid.
(C) The magnetic field lines of toroid are circular having common centre.
(D) Inside a solenoid, magnetic field may be made strong by passing small current and using laminated coil of soft iron.
Options:
Answer:
Solution:
Statement (A) is correct because a toroid is essentially a hollow circular ring on which a large number of turns of a wire are closely wound, which is equivalent to a solenoid bent into a closed ring.
Statement (B) is correct because inside a long solenoid, the magnetic field is uniform, meaning the field lines are straight and parallel to the axis.
Statement (C) is correct because the magnetic field lines inside a toroid form closed circular loops with a common centre.
Statement (D) is incorrect because the magnetic field inside a solenoid is given by . To produce a strong magnetic field, a large current must be passed through it, not a small current.
Answer: D
