The earth's magnetic field at a certain place has a horizontal component 0.3 Gauss and the total strength 0.5 Gauss. The angle of dip is

Options

A. `del = tan(-1)(4)/(3)`
B. `del = tan(-1)(3)/(4)`
C. `del = tan(-1)(5)/(3)`
D. `del = tan(-1)(3)/(5)`

Answer

A

Explanation

Horizontal component of earth's magnetic field is given by `B_(H) = B cos del (del =` Angle of dip)
or `cos del = (B_(H+))/(B) = (0.3)/(0.5) = (3)/(5)`
`:. (1)/(cos theta) = sec del = (5)/(3)`
Now, `tan del = sqrt(sec^(2)del - 1)`
`= sqrt(((5)/(3))^(2) - 1) = 1 sqrt((25)/(9) -1) = (4)/(3)`
`:. del = tan^(-1) ((4)/(3))`