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. |
1. | remains unchanged |
2. | \(+y\) by \((\mu-1)Af\) | is displaced along
3. | \(-y\) by \((\mu-1)Af\) | is displaced along
4. | \(+x\) by \((\mu-1)Af\) | is displaced along
1. | is parallel but wider. | 2. | is parallel but narrower. |
3. | is convergent. | 4. | is divergent. |
A beam of light is incident vertically on a glass slab of thickness \(1~\text{cm},\) and refractive index \(1.5.\) A fraction \(A\) is reflected from the front surface while another fraction \(B\) enters the slab and emerges after reflection from the back surface. The time delay between them is:
1. | \(10^{-10}~\text{s}\) | 2. | \(5\times 10^{-10}~\text{s}\) |
3. | \(10^{-11}~\text{s}\) | 4. | \(5\times 10^{-11}~\text{s}\) |
1. | \(\dfrac{R}{2}\) | 2. | \(\dfrac{R\sqrt3}{\sqrt3 +1}\) |
3. | \(\dfrac{R\sqrt3}{2}\) | 4. | \(\dfrac{R\sqrt3}{\sqrt3 -1}\) |
1. | \(BC.\) | normally from the surface
2. | \(AC.\) | normally from the surface
3. | \(BC\) or \(AC,\) normally. | either from the surface
4. | \(BC\) or \(AC,\) at an angle of emergence greater than \(60^{\circ}\) but less than \(90^{\circ}.\) | either from the surface
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. | \(\hat i+2\hat j+\hat k\) |
1. | \(\dfrac32\) | 2. | \(2\) |
3. | \(\sqrt{\dfrac32} \) | 4. | \(\sqrt2\) |