| Assertion (A): | If the phase difference between the light waves emerging from the slits of Young's experiment is \(\pi\) radian, the central fringe will be dark. |
| Reason (R): | Phase difference is equal to \((2\pi/\lambda)\) times of path difference. |
| 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. | Both (A) and (R) are False. |
| 1. | the fringes will disappear (uniform illumination). |
| 2. | screen will become dark. |
| 3. | the contrast between fringes will increase. |
| 4. | the contrast between fringes will decrease. |
| 1. | \(25\%\) | 2. | \(75\%\) |
| 3. | \(50\%\) | 4. | \(30\%\) |
| 1. | is conserved, gets redistributed |
| 2. | is equal at every point |
| 3. | is not conserved |
| 4. | is created in place of bright fringes |