BITSAT 2019 Slot 2 Solved Paper

For the given convex lens, focal length, f=25cm
Magnification of lens in term of u and f is given by
m=

f

f+u

=

25

25+u

........(i)
When the image is real, then m=−2 and u=−x1
∴ From Eq. (i), −2=

25

25−x1

⇒x1=

75

2

Again, when the image is virtual, then m=2 and u=−x2
∴ From Eq. (i), 2=

25

25−x2

⇒x2=

25

2

Hence, the ratio of x2 and x1 is
∴

x2

x1

=

25∕2

75∕2

=

1

3