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Derive the lens formula, (1)/(f)=(1)/(v)...

Derive the lens formula, `(1)/(f)=(1)/(v)-(1)/(u)` for a concave lens, using the necessary ray diagram.
Two lenses of powers 10 D and -5 D are placed in contact.
(i) Calculate the power of the new lens.
(ii) Where should an object be held from the lens, so as to obtain a virtual image of magnification 2?

Text Solution

AI Generated Solution

To derive the lens formula for a concave lens, we will follow these steps: ### Step 1: Ray Diagram 1. **Draw the Concave Lens**: Start by drawing a concave lens with its optical axis. 2. **Mark the Focal Points**: Mark the focal point (F) on the left side of the lens. For a concave lens, the focal point is virtual and located on the same side as the object. 3. **Place the Object**: Place an object (AB) on the left side of the lens. ### Step 2: Draw the Rays ...
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