Assertion: For best contrast between maxima and minima in the interference pattern of Young's double slit experiment, the intensity of light emerging out of the two slits should be equal.
Reason: The intensity of the interference pattern is proportional to square of amplitude.
1. Both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. Both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. Assertion is true but the reason is false.
4. Both the assertion and reason are false.
Assertion: The clouds in the sky generally appear to be whitish.
Reason: Diffraction due to clouds is efficient in equal measure at all wavelengths.
1. Both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. Both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. Assertion is true but the reason is false.
4. Both the assertion and reason are false.
Assertion: Crystalline solids can cause X-rays to diffract.
Reason: Interatomic distance in crystalline solids is of the order of 0.1 nm.
1. Both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. Both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. Assertion is true but the reason is false.
4. Both the assertion and reason are false.
Assertion: At the first glance, the top surface of the Morpho butterfly's wing appears a beautiful blue-green. If the wind moves the colour changes.
Reason: Different pigments in the wing reflect light at different angles.
1. Both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. Both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. Assertion is true but the reason is false.
4. Both the assertion and reason are false.
Given below are two statements:
Assertion (A): | In Young's double-slit experiment the two slits are at a distance d apart. The interference pattern is observed on a screen at a distance D from the slits and a dark fringe is observed. The wavelength of the wave is proportional to the square of the distance between two slits. |
Reason (R): | For a dark fringe, intensity is zero. |
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. |
Given below are two statements:
Assertion (A): | A double convex lens (μ=1.5) has a focal length 10 cm. When the lens is immersed in water (μ=43) its focal length becomes 20 cm. |
Reason (R): | 1f=μ1−μmμm(1R1−1R2) |
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. |
Assertion: Owls can move freely during night.
Reason: They have large number of rods on their retina.
Assertion: In optical fibre, the diameter of the core is kept small.
Reason: This smaller diameter of the core ensures that the fibre should have incident angle more than critical angle required for total internal reflection.
Given below are two statements:
Assertion (A): | The formula connecting u, v and f for a spherical mirror is valid only for mirrors whose sizes are very small compared to their radii of curvature. |
Reason (R): | Laws of reflection are strictly valid for plane surfaces, but not for large spherical mirrors. |
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. |
Assertion: The colour of the green flower seen through red glass appears to be dark.
Reason: Red glass transmits only red light.
1. Both the assertion and the reason are true and the reason is a correct explanation of the assertion.
2. Both the assertion and reason are true but the reason is not a correct explanation of the assertion.
3. Assertion is true but the reason is false.
4. Both the assertion and reason are false.