Question

At a certain place the angle of dip is 30° and the horizontal component of earth’s magnetic field is 0.5 G. The earth’s total magnetic field (in G), at that certain place, is ______.

Options

• `1/sqrt3`

• `1/2`

• `sqrt3`

• 1

Answer 1

At a certain place the angle of dip is 30° and the horizontal component of earth’s magnetic field is 0.5 G. The earth’s total magnetic field (in G), at that certain place, is `bb(1/sqrt3)`.

Explanation:

Angle of dip at a place is defined as angle between earth’s magnetic field and horizontal plane at that location.

δ→ Angle of Dip

On resolving `vec"B"` into two perpendicular components

B_H = B cos δ       ...(1)

B_V = B sin δ       ...(2)

Given horizontal component of earth’s magnetic field at a location is 0.5 G Using equation (1)

0.5 = B cos 30°

0.5 B × `sqrt3/2`

B = `(0.5 × 2)/sqrt3`

= `1/sqrt3`G