Magnification produced by a spherical mirror is given by the relation,
\(m=\frac{\text{Height of the image}}{\text{Height of the object}}\)
\(=-\frac{\text{Image distance}}{\text{Object distance}}\)
\(⇒ m=\frac{h_I}{h_o}=\frac{-v}{u}\)
Let the height of the object,\( h_o = h \)
Then, height of the image,\( h_I = −3h\) (Image formed is real)
\(-\frac{3h}{h}=\frac{-v}{u}\)
\(⇒\frac{v}{u}=3.\)
Object distance, u = −10 cm
v = 3 × (−10) = −30 cm
Here, the negative sign indicates that an inverted image is formed at a distance of 30 cm in front of the given concave mirror.
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |