Tardigrade
Tardigrade - CET NEET JEE Exam App
Exams
Login
Signup
Tardigrade
Question
Physics
A plano convex lenx (μ=1.5) has radius of curvature 20 cm. It is silvered on its plane surface. Find focal length after silvering:-
Q. A plano convex lenx
(
μ
=
1.5
)
has radius of curvature
20
c
m
. It is silvered on its plane surface. Find focal length after silvering:-
1586
180
Ray Optics and Optical Instruments
Report Error
A
10 cm
B
20 cm
C
15 cm
D
25 cm
Solution:
f
e
q
−
1
=
f
ℓ
2
−
f
m
1
f
m
=
∞
;
f
ℓ
1
=
(
1.5
−
1
)
{
20
1
}
=
40
1
So,
f
eg
1
=
−
40
2
⇒
f
eq
=
−
20
c
m