At a place, the horizontal component of earth's magnetic field is B and angle of dip is `60^(@)`. What is the value of horizontal component of the earth's magnetic field at equator ?

Explanation

`B_(H) = B` (i.e the horizontal component of earth's magnetic field `B_(H) = B` )
`I = 60^(@)` , (i.e the horizontal component of earth's magnetic field `B_(H) = B` )
` B_(H) = BE cos I " " (B_(E) ` - Net earth's magnetic field )
` B = B_(E) cos 60^(@) rArr B_(E) = B/(cos 60^(@)) rArr B_(E) = 2B`
`B_(H) = 2B`