Question

The value of the horizontal component of the earth's magnetic and angle dip are $1.8\times {10}^{-5}Wb/m^2$ and ${30}^{\circ }$ respectively at some place. The total intensity of the earth's magnetic field at that place will be:

• A. $3.16\times {10}^{-3}Wb/m^2$
• B. $3.67\times {10}^{-5}Wb/m^2$
• C. $5\times {10}^{-3}Wb/m^2$
• D. $2.08\times {10}^{-5}Wb/m^2$

Answer 1

The correct option is D $2.08\times {10}^{-5}Wb/m^2$

Given,

Horizontal component of earth's magnetic field, $B_H=1.8\times {10}^{-5}Wb/m^2$

Dip angle, ${\theta }_d={30}^0$

The total intensity of the earth's magnetic field will be,

$B=\frac{B_H}{cos{\theta }_d}$

$B=\frac{1.8\times {10}^{-5}}{cos{30}^0}=2.08\times {10}^{-5}Wb/m^2$

The correct option is option$\left(D\right)$.