1.

Deduce the relation f^(2) =ab , where 'a' and 'b' are the distance of an object and itsreal image from the principal focus and 'f' its focal length .

Answer»

Solution :GIVEN, u = F + a,v = f + b
SUBSTITUTING the values in the mirror equation, we GET`(1)/(f) = (1)/(u) + (1)/(v) = (1)/(f + a) + (1)/(f + b) `
`(1)/(f) = ((f + b) + (f + a ))/((f + a) (f + b)) = ( f + b + f + a)/(f^(2) + bf + af + AB)`
`f^(2) + bf + f^(2) + af = f^(2) + bf + af + ab"" therefore f^(2)= ab `


Discussion

No Comment Found

Related InterviewSolutions