99 Percentile Qs Bank for JEE MainPhysicsRay Optics
A thin convex lens of focal length f made of crown glass is immersed in a liquid of refractive index _I ( _I> _c ) , where _c is the refractive index of the crown glass. The convex lens now is
Options
- Aa convex lens of longer focal length
- Ba convex lens of shorter focal length
- Ca divergent lens
- Da convex lens of focal length ( _c- ₁ f
Correct answer
C. a divergent lens
Step-by-step solution
When the convex lens of focal length f made of crown glass immersed in liquid of refractive index _f ( _l> _c ) , here _c is the refractive index of crown glass, thus from lens maker's formula, we will get focal length of the lens as negative ( _e>u_c ) . Therefore, the convex lens will behave like a concave lens. So, it will be a divergent lens.