Question

The plane of the circular coil is held in the east-west direction. A steady current passed through the coil produces a magnetic field (B) equal to 2 times the horizontal component of the earth's magnetic field (BH) at the place. Now the plane of the coil is rotated carefully through an angle 45º about the vertical axis through its diameter. What is the deflection of the needle placed at the centre of the coil with respect to BH?

(a) tan⁻¹ 1/2
(b) tan⁻¹ 1/3
(c) tan⁻¹ 2
(d) tan⁻¹ 3

Answer 1

The deflection angle of the needle placed at the center of the coil with respect to the horizontal component of the Earth's magnetic field can be found using the tangent function.

Step-by-step explanation:

To find the deflection of the needle placed at the center of the coil with respect to BH, we can use trigonometry. The deflection angle can be found using the tangent function, where the opposite side is the magnetic field produced by the coil and the adjacent side is the horizontal component of the Earth's magnetic field.

Given that the magnetic field produced by the coil is 2 times the horizontal component of the Earth's magnetic field (BH), we can write the equation as:

tan(x) = opposite/adjacent

tan(x) = 2BH/BH = 2

Therefore, the deflection angle (x) is tan⁻¹(2).