CBSE
Multiple Choice QuestionsThe frequency of a light wave in a material is 2 × 1014 Hz and wavelength is 5000 Ao. The refractive index of material will be
1.50
3.00
1.33
1.40
Assertion: The frequencies of incident, reflected and refracted beam of monochromatic light passing from one medium to another are the same.
Reason: The incident, the reflected and refracted rays are coplanar.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: The sun rises some time before the actual sun-rise.
Reason: Because of the refraction through the different layers of atmosphere.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Resolving power of a telescope depends only on wavelength.
Reason: This is proportional to square of wavelength.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: If optical density of a substance is more than that of water then the mass density of substance can be less than water.
Reason: Optical density and mass density are not related.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: In optical fibre, the diameter of the core is kept small.
Reason: The smaller diameter of the core ensures that the fibres should have incident angle more than the critical angle required for total internal reflection.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
In a convex lens of focal length F, the minimum distance between an object and its real image must be
3F
4F
F
2F
Assertion: The edges of the images of white object formed by a concave mirror on the screen appear white.
Reason: Concave mirror does not suffer from chromatic aberration.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
The length of deviation for a glass prism is equal to its refracting angle. The refractive index of glass is 1.5. Then the angle of prism is
2 cos-1(3/4)
sin-1(3/4)
2 sin-1(3/2)
cos-1(3/2)
Assertion: A thick lens shows more chromatic aberration.
Reason: Thick lens behave as many thin lenses.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
