Ratio between total intensity of magnetic field at equator to poles is

Options

A. `1:1`
B. `1:2`
C. `2:1`
D. None of the above

Answer

A

Explanation

`B _(H) = B cos theta`
`B _(V) = B sin delta `
At equator, `delta = 0^(@)`
So, `B _(H) = B, B _(v) = 90^(@)`
At poles, `delta = 90^(@)`
So, `B _(H) = B , B _(v) = B`
So, the ratio of total intensity of magnetic field at equator to poles is 1:1