Question

1. If the magnitude of dispersive powers of two lenses
are 0.024 and 0.036. Then their focal lengths will
be for aberration free combination.
(1) 30 cm, -40 cm (2) 30 cm, -45 cm
(3) 10 cm, 30 cm (4) 20 cm, -35 cm​

Answer 1

Answer:

Again its a very simple question based on your previous question again the same short trick you can use here select the answer which is in the ratio of 0.024 and 0.036 so

The ratio is 2:3

And the option which has the same ratio as given in the question will be

2nd because :

30:45 is equal to 2 ratio 3 hope you understand this easy trick

Explanation: