a plano convex lens is made of flint glass its focal length is
Answers
Answer:
the same for all colours
Explanation:
focal length of lens is independent of wavelength
Answer:
F=10cm}⟹F=10cmWhen Curved surface is silvered then focal Lenght will be \color{red}{\sf 10cm}10cm
Explanation:
Refractive index (\mu)(μ) = 1.65
Radius of curvature of Convex side (R) = 33cm
\color{darkblue}\underline{\underline{\sf To \: Find-}}
ToFind−
Focal length of the plano convex lens if its convex surface is silvered.
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❏ When Curved Surface is silvered then -
\implies{\sf P = 2P_L + P_M}⟹P=2P
L
+P
M
\implies{\sf \dfrac{1}{F}=\dfrac{2}{f_{\ell}}+\dfrac{1}{f_m} }⟹
F
1
=
f
ℓ
2
+
f
m
1
\implies{\sf \dfrac{1}{F}=\dfrac{2(\mu-1)}{R}+\dfrac{2}{R} }⟹
F
1
=
R
2(μ−1)
+
R
2
\implies{\sf \dfrac{1}{F}=\dfrac{2\mu}{R}}⟹
F
1
=
R
2μ
\color{red}\blacksquare\underline{\boxed{\sf F=\dfrac{R}{2\mu}}}■
F=
2μ
R
\implies{\sf F =\dfrac{33}{2×1.65}}⟹F=
2×1.65
33
\implies{\sf F=\dfrac{33}{3.3}}⟹F=
3.3
33