A plano convex lens made of glass `(n=1.5)` has a focal length `10.0` cm.
(i) calculate the radius of curvature surface.
(ii) If an identical plano-convex lens is placed in contact with the first (plane surface facing each other), What will be the power of the combination ( in diopter) ?
(b) An astronomical telescope consists of two convex lenses having focal length `80` cm and `4` cm. When it is normal adjustment, what is its :
(i) length
(ii) Magnifying power ?

Explanation

Let's solve the problem step by step.

### Part (i): Calculate the radius of curvature of the plano-convex lens.

1. **Identify the given values:**
- Refractive index of glass, \( n = 1.5 \)
- Focal length of the lens, \( f = 10 \, \text{cm} \)

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