Question

The horizontal and vertical components of magnetic field of earth are same at some place on the surface of Earth. The magnetic dip angle at this place will be __________.

• A. ${30}^o$
• B. ${45}^o$
• C. $0^o$
• D. ${90}^o$

Answer 1

Answer: (B)

${45}^o$

The dip angle ‘A’ at a point is defined as the angle between the direction of the Earth’s magnetic field ‘B’ and the horizontal at that point on the surface of the Earth.

${\tan }^{-1}A=\frac{B_v}{B_h}$ (1)

$B_v=$ vertical component of earth’s magnetic field

$B_h=$ horizontal component of earth’s magnetic field

Given: $B_v=B_h$ (2)

Substituting (2) in (1)

Hence ${\tan }^{-1}A=\frac{B_h}{B_h}$

${\tan }^{-1}A=1$

$A={45}^{\circ }$

Hence the correct option is (B).