Question

Two short magnets having magnetic moments in the ratio 27 : 8, when placed on opposite sides of a deflection magnetometer, produce no deflection. If the distance of the weaker magnet is 0.12 m from the centre of deflection magnetometer, the distance of the stronger magnet from the centre is

• A. 0.06 m
• B. 0.08 m
• C. 0.12 m
• D. 0.18 m

Answer 1

Answer: (D)

0.18 m

Answer 2

$\frac { M _ { 1 } } { M _ { 2 } } = \left( \frac { d _ { 1 } } { d _ { 2 } } \right) ^ { 3 } \Rightarrow \frac { 27 } { 8 } = \left( \frac { d _ { 1 } } { 0.12 } \right) ^ { 3 }$

$\Rightarrow \frac { 3 } { 2 } = \frac { d _ { 1 } } { 0.12 } \Rightarrow 0.18 \mathrm {~m}$