Name: Hysteresis: Property of Ferromagnetic Substances
Uploaded: 2019-07-19
Duration: 5 min 6 s
Description: The behaviour of ferromagnets is fascinating. The magnetic field due to a ferromagnet exhibits an interesting phenomenon known as hysteresis. Let’s explore.

Question

Two bar magnets of length

0.1 m

and pole strength

75 Am

each, are placed on the same line. The distance between their centres is

0.2 m

. What is the resultant force due to one on the other when the north pole of one faces the south pole of the other and

Accepted Answer

The magnetic pole strength, $m = 75 A m$
The length of magnet, $0.2 m$
Distance between centre of magnet, $d = 0.2 m$

The force of repulsion between pole $N_{1}$ and $N_{2}$ is

$F_{1} = \frac{μ_{0}}{4 π} . \frac{m_{1} m_{2}}{r^{2}} = \frac{10^{- 7} \times 75 \times 75}{{(0 .2)}^{2}} = 1 .4 \times 10^{- 2} N$ Repulsive

The force of repulsion between pole $S_{1}$ and $S_{2}$ is

$F_{2} = \frac{μ_{0}}{4 π} . \frac{S_{1} S_{2}}{r^{2}} = \frac{10^{- 7} \times 75 \times 75}{{(0 .2)}^{2}} = 1 .4 \times 10^{- 2} N$ Repulsive

The force of attraction between pole $N_{1}$ and $S_{2}$ is

$F_{3} = \frac{μ_{0}}{4 π} . \frac{m_{1} m_{2}}{r^{2}} = \frac{10^{- 7} \times 75 \times 75}{{(0 .1)}^{2}} = 5 .6 \times 10^{- 2} N$ Attractive

The force of attraction between pole $N_{2}$ and $S_{1}$ is

$F_{4} = \frac{μ_{0}}{4 π} . \frac{m_{1} m_{2}}{r^{2}} = \frac{10^{- 7} \times 75 \times 75}{{(0 .3)}^{2}} = 6 .25 \times 10^{- 3} N$ Attractive

Net force,

$F_{n e t} = - F_{1} - F_{2} + F_{3} + F_{4}$

$= - 1 .4 \times 10^{- 2} - 1 .4 \times 10^{- 2} + 5 .6 \times 10^{- 2} + 6 .25 \times 10^{- 3}$

$= 3 .4 \times 10^{- 2} N$ Attractive

The force between magnet is $3 .4 \times 10^{- 2} N$ and attractive.

Two bar magnets of length $0.1 m$ and pole strength $75 Am$ each, are placed on the same line. The distance between their centres is $0.2 m$ . What is the resultant force due to one on the other when the north pole of one faces the south pole of the other and

Important Questions on Magnetism

Learn and Prepare for any exam you want !

Two bar magnets of length 0.1 m and pole strength 75 Am each, are placed on the same line. The distance between their centres is 0.2 m. What is the resultant force due to one on the other when the north pole of one faces the south pole of the other and

Important Questions on Magnetism

Learn and Prepare for any exam you want !

Two bar magnets of length $0.1 m$ and pole strength $75 Am$ each, are placed on the same line. The distance between their centres is $0.2 m$ . What is the resultant force due to one on the other when the north pole of one faces the south pole of the other and