A dip circle shows an apparent dip of `60^@` at a place where true dip is `45^@`. If dip circle is rotated through `90^@`, what apparent value of dip will it show?

Answer

51

Explanation

Here `delta_(1) = 60^(@) , delta= 45^(@) , delta_(2) = ? `
`cot^(2) delta_(1) +cot^(2) delta_(2)=cot^(2)delta`
`cot^(2) delta_(2) = cot^(2) delta -cot^(2)delta_(1)`
` = (cot 45^(@))^(2) - (cot 60^(@))^(2)`
` = 1- (1/(sqrt(3)))^(2)=2/3 = 0.67`
` cot delta_(2) = sqrt(0.67) = 0.816 `
` :. delta_(2) = cot^(-1) (0.816)=51^(@)`