Assume that the corner of \(O\) of the room is the origin, and the axes \(x,y,z\) are along the edges. The three walls meeting orthogonally at \(O\) are perfect mirrors. A ray of light travelling parallel to the vector \(-(\hat i+2\hat j+\hat k)\) is incident on the \(y\text-z\) mirror (wall). The emerging ray, after all reflections, will be along:
1. \(\hat i-2\hat j-\hat k\)
2. \(\hat i+\hat k-2\hat j\)
3. \(-\hat i+2\hat j+\hat k\)
4. \(\hat i+2\hat j+\hat k\)

Subtopic:  Reflection at Plane Surface |
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An equilateral triangular prism of glass \((\mu=1.5)\) is placed in air. A ray of light is incident normally onto the surface \(AB.\) The ray will finally emerge:
              
1. normally from the surface \(BC.\)
2. normally from the surface \(AC.\)
3. either from the surface \(BC\) or \(AC,\) normally.
4. either from the surface \(BC\) or \(AC,\) at an angle of emergence greater than \(60^{\circ}\) but less than \(90^{\circ}.\) 
Subtopic:  Total Internal Reflection |
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Given below are two statements: 
Assertion (A): If two converging lenses are introduced into the path of a parallel beam of light, the emerging beam cannot be diverging.
Reason (R): The converging lenses have positive powers.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. (A) is False but (R) is True.
Subtopic:  Lenses |
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A parallel beam of light of intensity \(I_0\) is incident on a lens and the intensity of the emerging beam is \(4I_0\) after it has traversed a further distance of \(30\) cm from the lens. The focal length of the lens is:
1. \(40\) cm
2. \(20\) cm
3. \(45\) cm
4. \(60\) cm
Subtopic:  Lenses |
 52%
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A parallel beam is incident on to a lens of focal length \(f\) (positive), parallel to its principal axis. A thin prism of vertex angle \(A\) and refractive index \(\mu\) is inserted in the path of the parallel beam before it falls on the lens. The focal point of the image:
1. remains unchanged
2. is displaced along \(+y\) by \((\mu-1)Af\)
3. is displaced along \(-y\) by \((\mu-1)Af\)
4. is displaced along \(+x\) by \((\mu-1)Af\)
Subtopic:  Prisms |
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A point object \((A)\) is placed on the principal axis of a convex lens (focal length = \(30~\text{cm}\)) at a distance of \(45~\text{cm}\) from it. The image is formed at position \(B.\) If the object \(A\) is moved up by \(1~\text{cm}\) then the image moves:
         
1. down by \(1~\text{cm}\)
2. down by \(2~\text{cm}\)
3. up by ​​​​​​​\(1~\text{cm}\)
4. up by ​​​​​​​\(2~\text{cm}\)
Subtopic:  Lenses |
 64%
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An incident ray falling at an angle of \(30^\circ\) with the \(x\)-axis is reflected by a mirror to a (reflected) ray making \(60^\circ\) with the \(x\)-axis. The angle made by the mirror's surface (not shown in the diagram) with the \(x\)-axis is:
            
1. \(15^\circ\)
2. \(45^\circ\)
3. \(75^\circ\)
4. \(105^\circ\)
Subtopic:  Reflection at Plane Surface |
 63%
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A ray of light falling on a \(2^\circ\)-prism (thin prism) undergoes a \(3^\circ\)-deviation on the first surface and no deviation on the second. The refractive index of the material of the prism is:
1. \(1.5\)
2. \(1.75\)
3. \(2.0\)
4. \(2.5\)
Subtopic:  Prisms |
 74%
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A ray of light \((1)\) gets reflected partially at the front surface of a thin film of thickness \(t,\) and refractive index \(\mu.\) The reflected ray from the front surface is \(2\) while that emerging due to reflection from the rear surface is \(3.\) Assume that ray \(1\) is incident normally. The optical path difference between rays \(2\) and \(3\) is:
1. \((\mu-1)t\) 2. \(2(\mu-1)t\)
3. \(\mu t\) 4. \(2\mu t\)
Subtopic:  Refraction at Plane Surface |
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If two convex lenses of powers \(P_1,P_2\) be placed close together, co-axially, the combination behaves as a lens of power:
1. \(P_1+P_2\) 2. \(|P_1-P_2|\)
3. \({\Large\frac{P^2_1}{P_2}}\) 4. \({\Large\frac{P^2_2}{P_1}}\)
Subtopic:  Lenses |
 86%
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