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Q. No.A small object is placed on the principal axis of a convex lens and it forms a real image with a (transverse) magnification of \(2.\) If the object were to move perpendicular to the principal axis with a speed \(u,\) the speed of the image will be:
| 1. | \(u\) | 2. | \(u/2\) |
| 3. | \(2u\) | 4. | \(4u\) |
Subtopic: Â Refraction at Curved Surface |
Level 3: 35%-60%
Hints
A solid sphere (centre \(O\)) of homogeneous transparent material kept upright has rays parallel to its vertical diameter falling on it. A ray that is aimed at \(P,\) where the horizontal distance \(OP=\dfrac{\sqrt3}{2}R\) (\(R\) being the sphere's radius), undergoes refraction at the sphere's surface and strikes the lowest point \(A.\)
Rays falling close to the highest point \((B)\) of the sphere are directed towards a point \(Q\) on the vertical diameter \(AB,\) after refraction. The distance \(BQ\) is:
Rays falling close to the highest point \((B)\) of the sphere are directed towards a point \(Q\) on the vertical diameter \(AB,\) after refraction. The distance \(BQ\) is:
| 1. | \(\dfrac{R}{2}\) | 2. | \(\dfrac{R\sqrt3}{\sqrt3 +1}\) |
| 3. | \(\dfrac{R\sqrt3}{2}\) | 4. | \(\dfrac{R\sqrt3}{\sqrt3 -1}\) |
Subtopic: Â Refraction at Curved Surface |
Level 3: 35%-60%
Please attempt this question first.
Hints
Please attempt this question first.
A solid sphere (centre \(O\)) of homogeneous transparent material kept upright has rays parallel to its vertical diameter falling on it. A ray that is aimed at \(P,\) where the horizontal distance \(OP=\dfrac{\sqrt3}{2}R\) (\(R\) being the sphere's radius), undergoes refraction at the sphere's surface and strikes the lowest point \(A.\)
The refractive index of the material of the sphere is:
1. \(2\)
2. \(\sqrt2\)
3. \(\sqrt3\)
4. \(\sqrt{\dfrac32} \)
The refractive index of the material of the sphere is:
1. \(2\)
2. \(\sqrt2\)
3. \(\sqrt3\)
4. \(\sqrt{\dfrac32} \)
Subtopic: Â Refraction at Curved Surface |
 52%
Level 3: 35%-60%
Please attempt this question first.
Hints
Please attempt this question first.
Two convex lenses \((L_1,~L_2) \) of focal lengths, \(20\text{ cm}\) \((L_1) \) and \(40\text{ cm}\) \((L_2),\) are placed co-axially at a separation of \(60\text{ cm}.\) If a parallel beam of light is incident on \(L_1, \) the emerging beam from \(L_2 :\)
1. is parallel but wider.
2. is parallel but narrower.
3. is convergent.
4. is divergent.
1. is parallel but wider.
2. is parallel but narrower.
3. is convergent.
4. is divergent.
Subtopic: Â Refraction at Curved Surface |
 56%
Level 3: 35%-60%
Hints
- 1(current)
Q. No.
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