CBSE
Multiple Choice QuestionsIn an interference, the intensity of two interfering waves are I and 4I respectively. They produce intensity at two points A and B with phase angle of and respectively. Then difference in between them is
I
2 I
4 I
5 I
Assertion: A white source of light during interference forms only white and black fringes.
Reason: Width of fringe is inversely proportional to the wavelength of the light used.
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 Young's double slit experiment, the two slits act as coherent sources of equal amplitude and of wavelength λ. In another experiment with the same set up, the two slits are sources of equal amplitude and wavelength λ, but are incoherent. The ratio of intensities of light at the midpoint of the screen in the first case to that in the second case is
2 : 1
1 : 2
3 : 4
4 : 3
Assertion: If objective and eye lenses of a microscope are interchanged then it can work as telescope.
Reason: The objective lens of telescope has small focal length.
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: Standard optical diffraction gratings cannot be used for discriminating between different X-ray wavelengths.
Reason: The grating spacing is not of the order of X-ray wavelengths.
If both assertion and reason are true and reason is the correct explanation of the assertion
If both assertion and reason are true but reason is not the correct explanation of the assertion
If assertion is true, but reason is false
Both assertion and reason are false statements
In Young's double slit experiment, the distance between two slits is made three times then the fridge width will become
9 times
1/9 times
3 times
1/3 times
Assertion: When white light fall on the compact disc, multicolours are seen after reflection.
Reason: CD disc behaves like a prism.
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 single slit diffraction with k = 500 nm and lens of diameter 0.1 mm then width of central maxima, obtain on screen at a distance of 1 m will be
5 mm
1 mm
10 mm
2.5 mm
If a street light of mass Mis suspended from the end of a uniform rod of length L in different possible patterns as shown in figure, then
pattern A is more sturdy
pattern B is more study
pattern C is more sturdy
all will have same sturdiness
Light is incident normally on a diffraction grating through which the first diffraction is seen at 32°. In this case the second order diffraction will be
at 80o
at 64o
at 48o
there is no second order diffraction
