Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the angle of dip at places $\mathrm{A}$ and $\mathrm{B}$ are $30^{\circ}$ and $45^{\circ}$ respectively, the ratio of horizontal component of earth's magnetic field at $A$ to that at $B$ will be $\left[\sin 45^{\circ}=\cos 45^{\circ}=\frac{1}{\sqrt{2}}, \quad \sin \frac{\pi}{6}=\frac{1}{2}, \quad \cos \frac{\pi}{6}=\frac{\sqrt{3}}{2}\right]$
PhysicsMagnetic Properties of MatterMHT CETMHT CET 2020 (16 Oct Shift 2)
Options:
  • A $\sqrt{2}: 1$
  • B $1: \sqrt{2}$
  • C $\sqrt{2}: \sqrt{3}$
  • D $\sqrt{3}: \sqrt{2}$
Solution:
1878 Upvotes Verified Answer
The correct answer is: $\sqrt{3}: \sqrt{2}$
(B)
The horizontal component of earth's magnetic field is given by,$H=R \cos \delta$ where, $\delta$ is the angle of dip so $\mathrm{H}_{1}=\mathrm{R} \cos 30^{\circ}$
and $\mathrm{H}_{2}=\mathrm{R} \cos 45^{\circ}$
$\therefore \frac{\mathrm{H}_{1}}{\mathrm{H}_{2}}=\frac{\mathrm{R} \cos 30^{\circ}}{\mathrm{R} \cos 45^{\circ}}=\frac{\sqrt{3} / 2}{1 / \sqrt{2}}=\frac{\sqrt{3}}{\sqrt{2}}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.