Question

A lens of power +2D and lens of power-1D are placed in close contact with each other .The combination will behave like????

Answer 1

Given:

A lens of power +2D and lens of power-1D are placed in close contact with each other.

To find:

Behaviour of the combination of lens.

Calculation:

Applying Formula for Combination Of Lens:

$\therefore \: \dfrac{1}{f} = \dfrac{1}{f1} + \dfrac{1}{f2}$

$= > \: p = p1 + p2$

$= > \: p = + 2D - 1D$

$= > \: p = + 1D$

So ,power and focal length are both positive.

Since net power is positive , hence the combination will behave as a convex lens (converging lens).

Extra information:

• Light rays from infinity will meet at the focus to for a real image after getting refracted from this combination.

Answer 2

Answer:

the answer is+1D

Explanation:

I think u got this answer