Choose the correct option (a) True dip is always equal to apparent dip. (b) True dip is not mathematically related to apparent dip. (c) True dip is less than the apparent dip. (d) True dip is always greater than the apparent dip.

Answer: (c). In a vertical plane at angle θ to the meridian only Hcos θ acts horizontally, so tan δ' = (tan δ)/(cos θ). cos θ ≤ 1 ⇒ tan δ' ≥ tan δ, i.e. apparent dip ≥ true dip. So true dip is less than the apparent dip: answer (c).

Choose the correct option | JEE Main 2021 (22 Jul, Shift 2)

Q4JEE Main 2021 · 22 JUL · SHIFT 2Easy

Earth's Magnetism

Choose the correct option

Show answer and solution

Answer: (c)

In a vertical plane at angle $\theta$ to the meridian only $H\cos\theta$ acts horizontally, so $\tan\delta' = \frac{\tan\delta}{\cos\theta}$ .
$\cos\theta \le 1 \Rightarrow \tan\delta' \ge \tan\delta$ , i.e. apparent dip $\ge$ true dip.
So true dip is less than the apparent dip: answer (c).

Report a mistake

Earth's Magnetism question from JEE Main 2021 (22 Jul, Shift 2)

More questions on Earth's Magnetism