Question

At two places A and B using vibration magnetometer, a magnet vibrates in a horizontal plane and its respective periodic time are 2 sec and 3 sec and at these places the earth's horizontal components are H_A and H_B respectively. Then the ratio between H_A and H_B will be

• A. 9 : 4
• B. 3 : 2
• C. 4 : 9
• D. 2 : 3

Answer 1

Answer: (A)

9 : 4

Answer 2

$\frac { T _ { A } } { T _ { B } } = \sqrt { \frac { H _ { B } } { H _ { A } } }$

⇒ $\frac { H _ { A } } { H _ { B } } =$ $\left( \frac { T _ { B } } { T _ { A } } \right) ^ { 2 } = \left( \frac { 3 } { 2 } \right) ^ { 2 } = \frac { 9 } { 4 }$.