282367
The convex side of a plano-convex lens of radius of curvature \(60 \mathrm{~cm}\) and refractive index 1.5 is silver plated to obtain a special type of concave mirror. The focal length of the mirror is
1 \(60 \mathrm{~cm}\)
2 \(30 \mathrm{~cm}\)
3 \(24 \mathrm{~cm}\)
4 \(120 \mathrm{~cm}\)
Explanation:
D: Given, \(\mathrm{R}_1=60 \mathrm{~cm}, \mathrm{R}_2=\infty, \mu=1.5\)
Using lens makers formula.
\(\begin{aligned}
\frac{1}{\mathrm{f}}=(\mu-1)\left(\frac{1}{\mathrm{R}_1}-\frac{1}{\mathrm{R}_2}\right) \\
\frac{1}{\mathrm{f}}=(1.5-1)\left(\frac{1}{60}-\frac{1}{\infty}\right) \\
\frac{1}{\mathrm{f}}=\frac{0.5}{60} \\
\mathrm{f}=120 \mathrm{~cm}
\end{aligned}\)
Focal length of the mirror is \(120 \mathrm{~cm}\)
UPSEE 2020
Ray Optics
282368
A thin lens of glass of refractive index 1.5 has focal length \(24 \mathrm{~cm}\) in air. It is now immersed in a liquid of refractive index \(\frac{9}{8}\). Its new focal length is
282369
The radius of curvature of the curved of a plano-convex lens is \(10 \mathrm{~cm}\). If the refractive index of the material of lens is 1.5 , then it will
1 Act as a convex lens only for the object that lie on its curved side
2 Act as a concave lens for the object that lie on its curved surface
3 Act as a convex lens irrespective of side on which the object lies
4 Act as a concave lens irrespective of side on which the object lies.
Explanation:
C: The radius of curvature of curved of a Planoconvex lens is \(10 \mathrm{~cm}\). if refractive index of material lens is 1.5 , then it will act as a convex lens irrespective of side on which the object has lies.
AP EAMCET-24.09.2020
Ray Optics
282370
A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the
1 focal length of the lens
2 radius of curvature of the curved surface
3 aperture of the lens
4 refractive index of the material
Explanation:
B: Spherometer is an instrument used for the precise measurement of the radius of curvature of a sphere or curved surface.
282367
The convex side of a plano-convex lens of radius of curvature \(60 \mathrm{~cm}\) and refractive index 1.5 is silver plated to obtain a special type of concave mirror. The focal length of the mirror is
1 \(60 \mathrm{~cm}\)
2 \(30 \mathrm{~cm}\)
3 \(24 \mathrm{~cm}\)
4 \(120 \mathrm{~cm}\)
Explanation:
D: Given, \(\mathrm{R}_1=60 \mathrm{~cm}, \mathrm{R}_2=\infty, \mu=1.5\)
Using lens makers formula.
\(\begin{aligned}
\frac{1}{\mathrm{f}}=(\mu-1)\left(\frac{1}{\mathrm{R}_1}-\frac{1}{\mathrm{R}_2}\right) \\
\frac{1}{\mathrm{f}}=(1.5-1)\left(\frac{1}{60}-\frac{1}{\infty}\right) \\
\frac{1}{\mathrm{f}}=\frac{0.5}{60} \\
\mathrm{f}=120 \mathrm{~cm}
\end{aligned}\)
Focal length of the mirror is \(120 \mathrm{~cm}\)
UPSEE 2020
Ray Optics
282368
A thin lens of glass of refractive index 1.5 has focal length \(24 \mathrm{~cm}\) in air. It is now immersed in a liquid of refractive index \(\frac{9}{8}\). Its new focal length is
282369
The radius of curvature of the curved of a plano-convex lens is \(10 \mathrm{~cm}\). If the refractive index of the material of lens is 1.5 , then it will
1 Act as a convex lens only for the object that lie on its curved side
2 Act as a concave lens for the object that lie on its curved surface
3 Act as a convex lens irrespective of side on which the object lies
4 Act as a concave lens irrespective of side on which the object lies.
Explanation:
C: The radius of curvature of curved of a Planoconvex lens is \(10 \mathrm{~cm}\). if refractive index of material lens is 1.5 , then it will act as a convex lens irrespective of side on which the object has lies.
AP EAMCET-24.09.2020
Ray Optics
282370
A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the
1 focal length of the lens
2 radius of curvature of the curved surface
3 aperture of the lens
4 refractive index of the material
Explanation:
B: Spherometer is an instrument used for the precise measurement of the radius of curvature of a sphere or curved surface.
282367
The convex side of a plano-convex lens of radius of curvature \(60 \mathrm{~cm}\) and refractive index 1.5 is silver plated to obtain a special type of concave mirror. The focal length of the mirror is
1 \(60 \mathrm{~cm}\)
2 \(30 \mathrm{~cm}\)
3 \(24 \mathrm{~cm}\)
4 \(120 \mathrm{~cm}\)
Explanation:
D: Given, \(\mathrm{R}_1=60 \mathrm{~cm}, \mathrm{R}_2=\infty, \mu=1.5\)
Using lens makers formula.
\(\begin{aligned}
\frac{1}{\mathrm{f}}=(\mu-1)\left(\frac{1}{\mathrm{R}_1}-\frac{1}{\mathrm{R}_2}\right) \\
\frac{1}{\mathrm{f}}=(1.5-1)\left(\frac{1}{60}-\frac{1}{\infty}\right) \\
\frac{1}{\mathrm{f}}=\frac{0.5}{60} \\
\mathrm{f}=120 \mathrm{~cm}
\end{aligned}\)
Focal length of the mirror is \(120 \mathrm{~cm}\)
UPSEE 2020
Ray Optics
282368
A thin lens of glass of refractive index 1.5 has focal length \(24 \mathrm{~cm}\) in air. It is now immersed in a liquid of refractive index \(\frac{9}{8}\). Its new focal length is
282369
The radius of curvature of the curved of a plano-convex lens is \(10 \mathrm{~cm}\). If the refractive index of the material of lens is 1.5 , then it will
1 Act as a convex lens only for the object that lie on its curved side
2 Act as a concave lens for the object that lie on its curved surface
3 Act as a convex lens irrespective of side on which the object lies
4 Act as a concave lens irrespective of side on which the object lies.
Explanation:
C: The radius of curvature of curved of a Planoconvex lens is \(10 \mathrm{~cm}\). if refractive index of material lens is 1.5 , then it will act as a convex lens irrespective of side on which the object has lies.
AP EAMCET-24.09.2020
Ray Optics
282370
A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the
1 focal length of the lens
2 radius of curvature of the curved surface
3 aperture of the lens
4 refractive index of the material
Explanation:
B: Spherometer is an instrument used for the precise measurement of the radius of curvature of a sphere or curved surface.
282367
The convex side of a plano-convex lens of radius of curvature \(60 \mathrm{~cm}\) and refractive index 1.5 is silver plated to obtain a special type of concave mirror. The focal length of the mirror is
1 \(60 \mathrm{~cm}\)
2 \(30 \mathrm{~cm}\)
3 \(24 \mathrm{~cm}\)
4 \(120 \mathrm{~cm}\)
Explanation:
D: Given, \(\mathrm{R}_1=60 \mathrm{~cm}, \mathrm{R}_2=\infty, \mu=1.5\)
Using lens makers formula.
\(\begin{aligned}
\frac{1}{\mathrm{f}}=(\mu-1)\left(\frac{1}{\mathrm{R}_1}-\frac{1}{\mathrm{R}_2}\right) \\
\frac{1}{\mathrm{f}}=(1.5-1)\left(\frac{1}{60}-\frac{1}{\infty}\right) \\
\frac{1}{\mathrm{f}}=\frac{0.5}{60} \\
\mathrm{f}=120 \mathrm{~cm}
\end{aligned}\)
Focal length of the mirror is \(120 \mathrm{~cm}\)
UPSEE 2020
Ray Optics
282368
A thin lens of glass of refractive index 1.5 has focal length \(24 \mathrm{~cm}\) in air. It is now immersed in a liquid of refractive index \(\frac{9}{8}\). Its new focal length is
282369
The radius of curvature of the curved of a plano-convex lens is \(10 \mathrm{~cm}\). If the refractive index of the material of lens is 1.5 , then it will
1 Act as a convex lens only for the object that lie on its curved side
2 Act as a concave lens for the object that lie on its curved surface
3 Act as a convex lens irrespective of side on which the object lies
4 Act as a concave lens irrespective of side on which the object lies.
Explanation:
C: The radius of curvature of curved of a Planoconvex lens is \(10 \mathrm{~cm}\). if refractive index of material lens is 1.5 , then it will act as a convex lens irrespective of side on which the object has lies.
AP EAMCET-24.09.2020
Ray Optics
282370
A plano-convex lens of unknown material and unknown focal length is given. With the help of a spherometer we can measure the
1 focal length of the lens
2 radius of curvature of the curved surface
3 aperture of the lens
4 refractive index of the material
Explanation:
B: Spherometer is an instrument used for the precise measurement of the radius of curvature of a sphere or curved surface.
