Question

how tolearn class 10 science ch 10​

Answer 1

only to clear your concept . this chap is not for learn if you practice all figure (the ray of light) in this chap you can easily write any ans .

Answer 2

There are some short cuts by which you can remember the ray diagrams.

As maths, the sign convention is similar in physics. just mug up the formulas and don't get confused between a mirror and a lens.