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A biconvex lens has a radius of curvature of magnitude 20 cm. Which one of the following options best describe the image formed of an object of height 2 cm placed 30 cm from the lens?
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- Virtual, upright, height = 1 cm
- Virtual, upright, height = 0.5 cm
- Real, inverted, height = 4 cm
- Real, inverted, height = 1cm
Correct Option: C
R = 20 cm
h0 = 2
u = –30 cm
| We have, | = (μ - 1) |  | - |  | |||
| f | R1 | R2 |
| = | | - 1 | |  | - | | - | |  | |||
| 2 | 20 | 20 |
| ⇒ | = | | - 1 | | × | |||
| f | 2 | 20 |
∴ f = 20 cm
| = | = | - | ⇒ | = | + | ||||||
| f | v | u | 20 | v | 30 |
| = | - | = | |||||
| v | 20 | 30 | 600 |
v = 60 cm
| m = | = | |||
| h0 | u |
| ⇒ hi = | × h0 = | × 2 = - 4 cm | ||
| u | 30 |
So, image is inverted.
