Question

Ravi is given lenses
with powers +5D, -5D,
+10D and -20D.
Considering a pair of
lenses at a time,
which two lenses will
he select to have a
combination of focal
length of -10 cm
when two lenses are
kept in contact in
case -10 cm.
A TOD and -20D
B
5D and -5D​

Answer 1

Answer:

Cotton clothes are thin and do not have space in which air can be trapped