Question

At a given place on the Earth’s surface, the horizontal component of Earth’s magnetic field is 9 × 10^-5 T and the resultant magnetic field is 180 × 10^-6. Calculate the angle of dip at this place.

(a) 45^o

(b) 0^o

(c) 60^o

(d) 30^o

The question was asked by my college director while I was bunking the class.

My question is from Earth’s Magnetism topic in section Magnetism and Matter of Physics – Class 12

Answer 1

Correct choice is (c) 60^o

The best explanation: Given: H = 9 × 10^-5; R = 180 × 10^-6 = 18 × 10^-5

The required equation ➔ H=Rcosδ

cosδ = \(\frac {H}{R}=\frac {9 \times 10^{-5}}{18 \times 10^{-5}}=\frac {1}{2}\)

Therefore, δ = cos^-1\(\frac {1}{2}\)=60^o

Thus, the angle of dip is 60^o.