We combined a convex lens of focal length f1 and concave lens of focal length f2 and their combined focal length was F. The combination of these lenses will be have like a concave lens, if:

Question

We combined a convex lens of focal length f1 and concave lens of focal length f2 and their combined focal length was F. The combination of these lenses will be have like a concave lens, if: (A) f1 le f2 (B) f1=f2 (C) f1< f2 (D) f1 > f2

Tardigrade Admin · Accepted Answer

If one of the lens is convex and the other is concave, then it behaves like concave lens, if f1 >f2 and it behaves like a convex lens if f1< f2. And it behave like a plane mirror if f1=f2.

Q. We combined a convex lens of focal length $f_{1}$ and concave lens of focal length $f_{2}$ and their combined focal length was $F$ . The combination of these lenses will be have like a concave lens, if:

$f_{1} \leq f_{2}$

$f_{1} = f_{2}$

$f_{1} < f_{2}$

$f_{1} > f_{2}$

If one of the lens is convex and the other is concave, then it behaves like concave lens, if $f_{1} > f_{2}$ and it behaves like a convex lens if $f_{1} < f_{2}$ . And it behave like a plane mirror if $f_{1} = f_{2}$ .

Q. We combined a convex lens of focal length f1​ and concave lens of focal length f2​ and their combined focal length was F. The combination of these lenses will be have like a concave lens, if:

f1​≤f2​

f1​=f2​

f1​<f2​

f1​>f2​