A short bar magnet has a magnetic moment of 0.65 J T-1, then the magnitude and direction of the magnetic field produced by the magnet at a distance 8 cm from the centre of magnet on the axis is

Question

A short bar magnet has a magnetic moment of 0.65 J T-1, then the magnitude and direction of the magnetic field produced by the magnet at a distance 8 cm from the centre of magnet on the axis is (A) 2.5 × 10-4 T, along NS direction (B) 2.5 × 10-4 T, along SN direction (C) 4.5 × 10-4 T, along NS direction (D) 4.5 × 10-4 T, along SN direction

Tardigrade Admin · Accepted Answer

Here, M=0.65 J T-1, d=8 cm =0.08 m The field produced by magnet at axial point is given by B=(μ0/4π) (2M/d3)=10-7×(2×0.65/(0.08)3) =2.5 × 10-4 T along SN

Q. A short bar magnet has a magnetic moment of $0.65 J T^{- 1}$ , then the magnitude and direction of the magnetic field produced by the magnet at a distance $8 c m$ from the centre of magnet on the axis is

$2.5 \times 1 0^{- 4} T$ , along $NS$ direction

$2.5 \times 1 0^{- 4} T$ , along $SN$ direction

$4.5 \times 1 0^{- 4} T$ , along $NS$ direction

$4.5 \times 1 0^{- 4} T$ , along $SN$ direction

Here, $M = 0.65 J T^{- 1}$ ,
$d = 8 c m$
$= 0.08 m$
The field produced by magnet at axial point is given by
$B = \frac{μ _{0}}{4 π} \frac{2 M}{d ^{3}} = 1 0^{- 7} \times \frac{2 \times 0.65}{( 0.08 ) ^{3}}$
$= 2.5 \times 1 0^{- 4} T$ along $SN$

Q. A short bar magnet has a magnetic moment of 0.65JT−1, then the magnitude and direction of the magnetic field produced by the magnet at a distance 8cm from the centre of magnet on the axis is

2.5×10−4T, along NS direction

2.5×10−4T, along SN direction

4.5×10−4T, along NS direction

4.5×10−4T, along SN direction