Question

A bar magnet is oscillating in the earth's magnetic field with time period T. If its mass is increased four times then its time period will be

• A. 4 T
• B. 2 T
• C. T
• D. T/2

Answer 1

Answer: (B)

2 T

Answer 2

$T = 2 \pi \sqrt { \frac { I } { M B _ { H } } }$ ; Where $I = \frac { \mathrm { w } \left( L ^ { 2 } + b ^ { 2 } \right) } { 12 }$

(w =Mass of magnet)

$\Rightarrow T \propto \sqrt { \mathrm { w } }$ If $T \rightarrow$Two times