What is the magnitude of the equatorial and axial fields due to a bar magnet of length 5.0 cm at a distance of 50 cm from its mid-point? The magnetic moment of the bar magnet is 0.40 Am 2.

Question

What is the magnitude of the equatorial and axial fields due to a bar magnet of length 5.0 cm at a distance of 50 cm from its mid-point? The magnetic moment of the bar magnet is 0.40 Am 2. (A) 3.2 × 10-6 T , 6.4 × 10-7 T (B) 4.2 × 105 T , 6 × 10-7 T (C) 5 × 10-6 T , 3.2 × 10-7 T (D) 3.2 × 10-7 T , 6.4 × 10-7 T

Tardigrade Admin · Accepted Answer

Magnetic field at equatorial line BE =(μ0 m/4 π r3)=(10-7 × 0.4/(0.5)3)=(10-7 × 0.4/0.125) =3.2 × 10-7 T Magnetic field at axial line BA=(μ0 2 m /4 π r3) =6.4 × 10-7 T

Q. What is the magnitude of the equatorial and axial fields due to a bar magnet of length $5.0 c m$ at a distance of $50 c m$ from its mid-point? The magnetic moment of the bar magnet is $0.40 A m^{2}$ .

$3.2 \times 1 0^{- 6} T, 6.4 \times 1 0^{- 7} T$

$4.2 \times 1 0^{5} T, 6 \times 1 0^{- 7} T$

$5 \times 1 0^{- 6} T, 3.2 \times 1 0^{- 7} T$

$3.2 \times 1 0^{- 7} T, 6.4 \times 1 0^{- 7} T$

Magnetic field at equatorial line
$B_{E} = \frac{μ _{0} m}{4 π r ^{3}} = \frac{1 0 ^{- 7} \times 0.4}{( 0.5 ) ^{3}} = \frac{1 0 ^{- 7} \times 0.4}{0.125}$
$= 3.2 \times 1 0^{- 7} T$
Magnetic field at axial line $B_{A} = \frac{μ _{0} 2 m}{4 π r ^{3}}$
$= 6.4 \times 1 0^{- 7} T$

Q. What is the magnitude of the equatorial and axial fields due to a bar magnet of length 5.0cm at a distance of 50cm from its mid-point? The magnetic moment of the bar magnet is 0.40Am2.

3.2×10−6T,6.4×10−7T

4.2×105T,6×10−7T

5×10−6T,3.2×10−7T

3.2×10−7T,6.4×10−7T