Given below are two statements: 
Assertion (A): Parallel rays of light of different colours fail to converge to a point after reflection from a spherical mirror. 
Reason (R): The refractive index of any material depends on the frequency of light. 
 
1. (A) is True but (R) is False.
2. (A) is False but (R) is True.
3. Both (A) and (R) are True and (R) is the correct explanation of (A).
4. Both (A) and (R) are True but (R) is not the correct explanation of (A).

Subtopic:  Reflection at Spherical Surface |
Level 4: Below 35%
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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:  Refraction at Curved Surface |
Level 3: 35%-60%
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An equi-convex lens of focal length \(20\) cm (in the air) is split into two parts by a surface that has half the curvature of either of its outer surfaces. The ratio of the powers of the two lenses thus formed is:
1. \(3:1\)
2. \(2:1\)
3. \(1:1\)
4. \(-2:1\)
Subtopic:  Lenses |
Level 4: Below 35%
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An equi-convex lens of focal length \(50~\text{cm}\) and an equi-concave lens of the same focal length are placed \(50~\text{cm}\) apart, with a common principal axis. A point object is placed on the principal axis of the system, at a distance of \(100~\text{cm}\) in front of the convex lens (see figure). The final image is formed at:
            
1. \(100~\text{cm}\) in front of the concave lens
2. \(50~\text{cm}\) in front of the concave lens
3. \(50~\text{cm}\) behind the concave lens
4. infinity
Subtopic:  Lenses |
 58%
Level 3: 35%-60%
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A plano-convex lens made of glass \((\mu=1.5)\) is placed with its convex surface in a liquid, and it is found that the focal length is doubled. The refractive index of the liquid is:
1. \(3\)
2. \(2\)
3. \(1.25\)
4. \(1.2\)
Subtopic:  Lenses |
Level 3: 35%-60%
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An equiconvex lens of focal length \(100\) cm is split into two plano-convex lenses and the plane surface of one of these lenses is silvered. This acts as a:
1. converging mirror of focal length \(200\) cm.
2. converging mirror of focal length \(100\) cm.
3. diverging mirror of focal length \(200\) cm.
4. diverging mirror of focal length \(100\) cm.
Subtopic:  Lenses |
Level 3: 35%-60%
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Two identical equilateral triangular prisms, each of which gives a minimum deviation of \(60^{\circ}\) are taken: call these prisms \(A,B\). These are placed as shown in the figure, and a ray of light is incident on prism \(A\) at minimum deviation. Now prism \(B\) is cut in half, along the dotted line, and the right half is removed. The deviation of the emerging ray is:
           
1. \(90^{\circ}\) 2. \(45^{\circ}\)
3. \(60^{\circ}\) 4. \(30^{\circ}\)
Subtopic:  Prisms |
 50%
Level 3: 35%-60%
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The following diagram shows light travelling from \(A\) to \(B\) after bouncing off a plane mirror at \(P.\) The time taken is \(t_{APB} .\) If, however, light were to take a different path, \(AQB\) (shown by the dotted line), the time taken is \(t_{AQB}.\) 
Then, 
                         
1. \(t_{APB}=t_{AQB}\)
2. \(t_{APB}<t_{AQB}\)
3. \(t_{APB}>t_{AQB}\)
4. \(t_{APB}\) may be greater than or less than \(t_{AQB}\) depending on whether \(Q\) is to the left or right of \(P.\)
Subtopic:  Reflection at Plane Surface |
Level 4: Below 35%
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A thin equi-convex lens of refractive index \(1.2\) is dipped in oil of index \(1.44.\) The lens has a power of \(2\) D (in air). When it is immersed in the oil, the focal length of the lens becomes:
1. \(50\) cm 2. \(-50\) cm
3. \(-50/1.2\) cm 4. \(-50 \times1.2\) cm
Subtopic:  Lens Makers' Formula |
 57%
Level 3: 35%-60%
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A ray of light is incident normally onto the surface \(AB\)  of a right-angled prism \({ABC}\) \((\angle B=90^\circ)\) and emerges from the surface \({AC}.\) The refractive index of the material of the prism is \((\mu = \sqrt 2).\)
                     
The ray undergoes a deviation of:
1. \(15^\circ\)
2. \(30^\circ\)
3. \(45^\circ\)
4. \(60^\circ\)
Subtopic:  Prisms |
 55%
Level 3: 35%-60%
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