Question

The time of vibration of a dip needle vibration in the vertical plane in the magnetic meridian is 3s. When the same magnetic needle is made to vibrate in the horizontal plane, the time of vibration is 3$\sqrt { 2 }$s. Then angle of dip will be-

• A. 90⁰
• B. 60⁰
• C. 45⁰
• D. 30⁰

Answer 1

Answer: (B)

60⁰

Answer 2

In magnetic meridian 3 = $2 \pi \sqrt { \frac { \mathrm { I } } { \mathrm { MH } } }$…(2)

∴

⇒ θ = 60⁰