Class 12 Physics simulations · Moving Charges and Magnetism

Magnetic field on the axis of a loop

Pass current through a circular coil and move a probe along its axis.

Open the simulation

What to notice

The field is strongest at the centre and falls off as 1/x³ far from the coil.

Key relation

B = μ₀NIR² / 2(R² + x²)^(3/2)

Try this

Move the probe to x = R. What fraction of the centre field remains?

What you can change

• Current I: 1 to 20 A
• Turns N: 1 to 100
• Loop radius R: 2 to 20 cm
• Probe position x: -30 to 30 cm

More in Moving Charges and Magnetism

• Cyclotron frequency
• Force on a current-carrying wire
• Helical motion in a magnetic field
• Charged particle in a field
• Galvanometer to ammeter or voltmeter
• Moving-coil galvanometer
• Force between parallel currents
• Magnetic field inside a solenoid
• Crossed fields: the velocity selector

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