The horizontal component of the earth's magnetic field is `3.6 xx 10^(-5) T` where the dip is `60^@`. Find the magnitude of the earth's magnetic field.

Options

A. `2.8xx10^(-4)` tesla
B. `2.1xx20^(-4)` tesla
C. `7.2xx10^(-5)` tesla
D. `3.6xx10^(-5)` tesla

Answer

c

Explanation

(c) Horizontal component of earth.s field , `H= B cos thetqa,`
`since, theta =60^(@)`
`3.6xx10^(-5)=Bxx(1)/(2) rArr B=7.2xx10^(-5) ` Tesla