⚛️ Physics · Magnetism and Matter · NEET & JEE

In a vibration magnetometer, the time period is T = 2π√(I/mB). If the magnetic field is made four times stronger, the period:

Answer: halves.

A halves
B doubles
C becomes four times
D is unchanged

Correct answer: A. halves

Explanation: T ∝ 1/√B, so 4× field gives T/2 - it halves.

Magnetic field lines of a bar magnet, emerging from the north pole and curving round to enter the south pole outside the magnet

Magnetic field of a bar magnet: field lines emerge from the north pole and re-enter at the south pole outside the magnet, forming continuous closed loops. Image: Geek3, CC BY-SA 3.0, via Wikimedia Commons.

Concept context

Bar magnets, Earth's magnetism, and how different materials respond to an external magnetic field - diamagnetic, paramagnetic, and ferromagnetic behaviour.

Read the full Magnetism and Matter notes →

In a vibration magnetometer, the time period is T = 2π√(I/mB). If the magnetic field is made four times stronger, the period:

Concept context

More Magnetism and Matter questions