1.

Assertion (A) : A double convex lens (n_(g)=1.5) has a focal length of 10 cm in air. When the lens is immersed in a medium of refractive index n_(m)=(4)/(3), its focal length becomes 40 cm. Reason (R ) : (1)/(f)=((n_(g))/(n_(m))-1)((1)/(R_(1))-(1)/(R_(2)))

Answer»

If both ASSERTION and REASON are true and the reason is the CORRECT explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true but reason is FALSE.
If the assertion is false but reason is true.

Solution :`1/10 =(1.5/1 -1)(1/R_(1)-1/R_(2))` and `1/f =(1.5/(4/3) -1) (1/R_(1) -1/R_(2))`
On simplification, we get `f=+40 CM`


Discussion

No Comment Found

Related InterviewSolutions