Question

The horizontal component of earth’s magnetic field at a place is \(0.4 \times 10^{-4}\,T\). If the angle of dip is \(45^\circ\), the value of total intensity is:

• A. \(0.5 \times 10^{-4}\,T\)
• B. \(0.4 \times 10^{-4}\,T\)
• C. \(0.5 \times 10^{-6}\,T\)
• D. \(0.4 \times 10^{-6}\,T\)

Hint:

Use \( B = \frac{B_H}{\cos\theta} \).

Answer 1

The Correct Option is A

Concept: \[ B_H = B \cos\theta \]

Step 1: Rearrange.
\[ B = \frac{B_H}{\cos\theta} \]

Step 2: Substitute.
\[ B = \frac{0.4 \times 10^{-4}}{\cos 45^\circ} = \frac{0.4 \times 10^{-4}}{\frac{1}{\sqrt{2}}} = 0.5 \times 10^{-4} \]