Points A and B are situated perpendicular to the axis of a 2 cm long bar magnet at large distance X and 3 X from its centre on opposite sides. The ratio of the magnetic fields at A and B will be approximately equal to

Question

Points A and B are situated perpendicular to the axis of a 2 cm long bar magnet at large distance X and 3 X from its centre on opposite sides. The ratio of the magnetic fields at A and B will be approximately equal to (A) 1: 9 (B) 2: 9 (C) 27: 1 (D) 9: 1

Tardigrade Admin · Accepted Answer

B propto (1/x3) ⇒ (B1/B2)=((x2/x1))3=((3 x/x))3=(27/1)

Q. Points $A$ and $B$ are situated perpendicular to the axis of a $2 c m$ long bar magnet at large distance $X$ and $3 X$ from its centre on opposite sides. The ratio of the magnetic fields at $A$ and $B$ will be approximately equal to

1 : 9

2 : 9

27 : 1

9 : 1

$B \propto \frac{1}{x ^{3}} \Rightarrow \frac{B _{1}}{B _{2}} = (\frac{x _{2}}{x _{1}})^{3} = (\frac{3 x}{x})^{3} = \frac{27}{1}$

Q. Points A and B are situated perpendicular to the axis of a 2cm long bar magnet at large distance X and 3X from its centre on opposite sides. The ratio of the magnetic fields at A and B will be approximately equal to