282527
Assertion: Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
AThe radius of curvature of lens in both side are same magnitude.
AIIMS-2007
Ray Optics
282528
Assertion: Position of image approaches focus of a lens, only when object approaches infinity.
Reason: Paraxial rays incident parallel to principle axis intersect at the focus after refraction from lens.
1 If both Assertion and Reason are correct and reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
3 If Assertion is correct but Reason is incorrect
4 If both the Assertion and Reason are incorrect
Explanation:
ABoth Assertion and Reason are correct and reason is the correct explanation of assertion.
AIIMS-2010
Ray Optics
282529
Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.
Reason: The refractive index of water is smaller than the refractive index of air.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
D: The refractive index of air is 1. And refractive index of water is \(\frac{4}{3}\).
Therefore assertion and reason both is incorrect.
Ray Optics
282530
A plano-convex lens of focal length \(30 \mathrm{~cm}\), has its plane surface silvered. An object is placed \(40 \mathrm{~cm}\) from the lens on the convex side. The distance of the image from the lens is
1 \(18 \mathrm{~cm}\)
2 \(24 \mathrm{~cm}\)
3 \(30 \mathrm{~cm}\)
4 \(40 \mathrm{~cm}\)
Explanation:
B: Given, Focus of Plano convex lens \(\left(f_1\right)=\) \(30 \mathrm{~cm}\) and focus of plane side \(\left(\mathrm{f}_2\right)=\infty\)
Then, equivalent focus,
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{2}{\mathrm{f}_1}+\frac{2}{\mathrm{f}_2} \\
\mathrm{P}_{\text {total }}=\frac{1}{\mathrm{f}^{\prime}} \\
\mathrm{f}=15 \mathrm{~cm}
\end{aligned}\)
The silvered lens behaves as concave mirror of focal length \(15 \mathrm{~cm}\).
Then, from mirror formula
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{u}}+\frac{1}{\mathrm{v}} \\
\frac{1}{-15}=\frac{1}{-40}+\frac{1}{\mathrm{v}} \\
\frac{1}{\mathrm{v}}=\frac{1}{40}-\frac{1}{15} \\
\frac{1}{\mathrm{v}}=\frac{3-8}{120} \\
\mathrm{v}=\frac{120}{-5} \\
\mathrm{v}=-24 \mathrm{~cm}
\end{aligned}\)
AIIMS-2013
Ray Optics
282531
The focal length of a converging lens are \(f_V\) and \(f_R\) for violet and red light respectively . They
1 \(f_V>f_R\)
2 \(f_V=f_R\)
3 \(f_V
4 any of the three is possible depending on the value of the average refractive index \(\mu\).
Explanation:
C: Focal length is directly proportional to wavelength of light passed. As red light has higher wavelength, it reflect less and has greater focal length. On the other hand, violet light converges more and has small focal length.
\(\mathrm{f}_{\mathrm{V}}<\mathrm{f}_{\mathrm{R}}\)
282527
Assertion: Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
AThe radius of curvature of lens in both side are same magnitude.
AIIMS-2007
Ray Optics
282528
Assertion: Position of image approaches focus of a lens, only when object approaches infinity.
Reason: Paraxial rays incident parallel to principle axis intersect at the focus after refraction from lens.
1 If both Assertion and Reason are correct and reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
3 If Assertion is correct but Reason is incorrect
4 If both the Assertion and Reason are incorrect
Explanation:
ABoth Assertion and Reason are correct and reason is the correct explanation of assertion.
AIIMS-2010
Ray Optics
282529
Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.
Reason: The refractive index of water is smaller than the refractive index of air.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
D: The refractive index of air is 1. And refractive index of water is \(\frac{4}{3}\).
Therefore assertion and reason both is incorrect.
Ray Optics
282530
A plano-convex lens of focal length \(30 \mathrm{~cm}\), has its plane surface silvered. An object is placed \(40 \mathrm{~cm}\) from the lens on the convex side. The distance of the image from the lens is
1 \(18 \mathrm{~cm}\)
2 \(24 \mathrm{~cm}\)
3 \(30 \mathrm{~cm}\)
4 \(40 \mathrm{~cm}\)
Explanation:
B: Given, Focus of Plano convex lens \(\left(f_1\right)=\) \(30 \mathrm{~cm}\) and focus of plane side \(\left(\mathrm{f}_2\right)=\infty\)
Then, equivalent focus,
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{2}{\mathrm{f}_1}+\frac{2}{\mathrm{f}_2} \\
\mathrm{P}_{\text {total }}=\frac{1}{\mathrm{f}^{\prime}} \\
\mathrm{f}=15 \mathrm{~cm}
\end{aligned}\)
The silvered lens behaves as concave mirror of focal length \(15 \mathrm{~cm}\).
Then, from mirror formula
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{u}}+\frac{1}{\mathrm{v}} \\
\frac{1}{-15}=\frac{1}{-40}+\frac{1}{\mathrm{v}} \\
\frac{1}{\mathrm{v}}=\frac{1}{40}-\frac{1}{15} \\
\frac{1}{\mathrm{v}}=\frac{3-8}{120} \\
\mathrm{v}=\frac{120}{-5} \\
\mathrm{v}=-24 \mathrm{~cm}
\end{aligned}\)
AIIMS-2013
Ray Optics
282531
The focal length of a converging lens are \(f_V\) and \(f_R\) for violet and red light respectively . They
1 \(f_V>f_R\)
2 \(f_V=f_R\)
3 \(f_V
4 any of the three is possible depending on the value of the average refractive index \(\mu\).
Explanation:
C: Focal length is directly proportional to wavelength of light passed. As red light has higher wavelength, it reflect less and has greater focal length. On the other hand, violet light converges more and has small focal length.
\(\mathrm{f}_{\mathrm{V}}<\mathrm{f}_{\mathrm{R}}\)
282527
Assertion: Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
AThe radius of curvature of lens in both side are same magnitude.
AIIMS-2007
Ray Optics
282528
Assertion: Position of image approaches focus of a lens, only when object approaches infinity.
Reason: Paraxial rays incident parallel to principle axis intersect at the focus after refraction from lens.
1 If both Assertion and Reason are correct and reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
3 If Assertion is correct but Reason is incorrect
4 If both the Assertion and Reason are incorrect
Explanation:
ABoth Assertion and Reason are correct and reason is the correct explanation of assertion.
AIIMS-2010
Ray Optics
282529
Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.
Reason: The refractive index of water is smaller than the refractive index of air.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
D: The refractive index of air is 1. And refractive index of water is \(\frac{4}{3}\).
Therefore assertion and reason both is incorrect.
Ray Optics
282530
A plano-convex lens of focal length \(30 \mathrm{~cm}\), has its plane surface silvered. An object is placed \(40 \mathrm{~cm}\) from the lens on the convex side. The distance of the image from the lens is
1 \(18 \mathrm{~cm}\)
2 \(24 \mathrm{~cm}\)
3 \(30 \mathrm{~cm}\)
4 \(40 \mathrm{~cm}\)
Explanation:
B: Given, Focus of Plano convex lens \(\left(f_1\right)=\) \(30 \mathrm{~cm}\) and focus of plane side \(\left(\mathrm{f}_2\right)=\infty\)
Then, equivalent focus,
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{2}{\mathrm{f}_1}+\frac{2}{\mathrm{f}_2} \\
\mathrm{P}_{\text {total }}=\frac{1}{\mathrm{f}^{\prime}} \\
\mathrm{f}=15 \mathrm{~cm}
\end{aligned}\)
The silvered lens behaves as concave mirror of focal length \(15 \mathrm{~cm}\).
Then, from mirror formula
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{u}}+\frac{1}{\mathrm{v}} \\
\frac{1}{-15}=\frac{1}{-40}+\frac{1}{\mathrm{v}} \\
\frac{1}{\mathrm{v}}=\frac{1}{40}-\frac{1}{15} \\
\frac{1}{\mathrm{v}}=\frac{3-8}{120} \\
\mathrm{v}=\frac{120}{-5} \\
\mathrm{v}=-24 \mathrm{~cm}
\end{aligned}\)
AIIMS-2013
Ray Optics
282531
The focal length of a converging lens are \(f_V\) and \(f_R\) for violet and red light respectively . They
1 \(f_V>f_R\)
2 \(f_V=f_R\)
3 \(f_V
4 any of the three is possible depending on the value of the average refractive index \(\mu\).
Explanation:
C: Focal length is directly proportional to wavelength of light passed. As red light has higher wavelength, it reflect less and has greater focal length. On the other hand, violet light converges more and has small focal length.
\(\mathrm{f}_{\mathrm{V}}<\mathrm{f}_{\mathrm{R}}\)
282527
Assertion: Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
AThe radius of curvature of lens in both side are same magnitude.
AIIMS-2007
Ray Optics
282528
Assertion: Position of image approaches focus of a lens, only when object approaches infinity.
Reason: Paraxial rays incident parallel to principle axis intersect at the focus after refraction from lens.
1 If both Assertion and Reason are correct and reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
3 If Assertion is correct but Reason is incorrect
4 If both the Assertion and Reason are incorrect
Explanation:
ABoth Assertion and Reason are correct and reason is the correct explanation of assertion.
AIIMS-2010
Ray Optics
282529
Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.
Reason: The refractive index of water is smaller than the refractive index of air.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
D: The refractive index of air is 1. And refractive index of water is \(\frac{4}{3}\).
Therefore assertion and reason both is incorrect.
Ray Optics
282530
A plano-convex lens of focal length \(30 \mathrm{~cm}\), has its plane surface silvered. An object is placed \(40 \mathrm{~cm}\) from the lens on the convex side. The distance of the image from the lens is
1 \(18 \mathrm{~cm}\)
2 \(24 \mathrm{~cm}\)
3 \(30 \mathrm{~cm}\)
4 \(40 \mathrm{~cm}\)
Explanation:
B: Given, Focus of Plano convex lens \(\left(f_1\right)=\) \(30 \mathrm{~cm}\) and focus of plane side \(\left(\mathrm{f}_2\right)=\infty\)
Then, equivalent focus,
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{2}{\mathrm{f}_1}+\frac{2}{\mathrm{f}_2} \\
\mathrm{P}_{\text {total }}=\frac{1}{\mathrm{f}^{\prime}} \\
\mathrm{f}=15 \mathrm{~cm}
\end{aligned}\)
The silvered lens behaves as concave mirror of focal length \(15 \mathrm{~cm}\).
Then, from mirror formula
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{u}}+\frac{1}{\mathrm{v}} \\
\frac{1}{-15}=\frac{1}{-40}+\frac{1}{\mathrm{v}} \\
\frac{1}{\mathrm{v}}=\frac{1}{40}-\frac{1}{15} \\
\frac{1}{\mathrm{v}}=\frac{3-8}{120} \\
\mathrm{v}=\frac{120}{-5} \\
\mathrm{v}=-24 \mathrm{~cm}
\end{aligned}\)
AIIMS-2013
Ray Optics
282531
The focal length of a converging lens are \(f_V\) and \(f_R\) for violet and red light respectively . They
1 \(f_V>f_R\)
2 \(f_V=f_R\)
3 \(f_V
4 any of the three is possible depending on the value of the average refractive index \(\mu\).
Explanation:
C: Focal length is directly proportional to wavelength of light passed. As red light has higher wavelength, it reflect less and has greater focal length. On the other hand, violet light converges more and has small focal length.
\(\mathrm{f}_{\mathrm{V}}<\mathrm{f}_{\mathrm{R}}\)
282527
Assertion: Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
AThe radius of curvature of lens in both side are same magnitude.
AIIMS-2007
Ray Optics
282528
Assertion: Position of image approaches focus of a lens, only when object approaches infinity.
Reason: Paraxial rays incident parallel to principle axis intersect at the focus after refraction from lens.
1 If both Assertion and Reason are correct and reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
3 If Assertion is correct but Reason is incorrect
4 If both the Assertion and Reason are incorrect
Explanation:
ABoth Assertion and Reason are correct and reason is the correct explanation of assertion.
AIIMS-2010
Ray Optics
282529
Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.
Reason: The refractive index of water is smaller than the refractive index of air.
1 If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
2 If both Assertion and Reason are correct but Reason in not a correct explanation of the Assertion.
3 If the Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.
Explanation:
D: The refractive index of air is 1. And refractive index of water is \(\frac{4}{3}\).
Therefore assertion and reason both is incorrect.
Ray Optics
282530
A plano-convex lens of focal length \(30 \mathrm{~cm}\), has its plane surface silvered. An object is placed \(40 \mathrm{~cm}\) from the lens on the convex side. The distance of the image from the lens is
1 \(18 \mathrm{~cm}\)
2 \(24 \mathrm{~cm}\)
3 \(30 \mathrm{~cm}\)
4 \(40 \mathrm{~cm}\)
Explanation:
B: Given, Focus of Plano convex lens \(\left(f_1\right)=\) \(30 \mathrm{~cm}\) and focus of plane side \(\left(\mathrm{f}_2\right)=\infty\)
Then, equivalent focus,
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{2}{\mathrm{f}_1}+\frac{2}{\mathrm{f}_2} \\
\mathrm{P}_{\text {total }}=\frac{1}{\mathrm{f}^{\prime}} \\
\mathrm{f}=15 \mathrm{~cm}
\end{aligned}\)
The silvered lens behaves as concave mirror of focal length \(15 \mathrm{~cm}\).
Then, from mirror formula
\(\begin{aligned}
\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{u}}+\frac{1}{\mathrm{v}} \\
\frac{1}{-15}=\frac{1}{-40}+\frac{1}{\mathrm{v}} \\
\frac{1}{\mathrm{v}}=\frac{1}{40}-\frac{1}{15} \\
\frac{1}{\mathrm{v}}=\frac{3-8}{120} \\
\mathrm{v}=\frac{120}{-5} \\
\mathrm{v}=-24 \mathrm{~cm}
\end{aligned}\)
AIIMS-2013
Ray Optics
282531
The focal length of a converging lens are \(f_V\) and \(f_R\) for violet and red light respectively . They
1 \(f_V>f_R\)
2 \(f_V=f_R\)
3 \(f_V
4 any of the three is possible depending on the value of the average refractive index \(\mu\).
Explanation:
C: Focal length is directly proportional to wavelength of light passed. As red light has higher wavelength, it reflect less and has greater focal length. On the other hand, violet light converges more and has small focal length.
\(\mathrm{f}_{\mathrm{V}}<\mathrm{f}_{\mathrm{R}}\)
