Wave Optics - Online Test
Q1. In the single slit diffraction, every point on the slit acts-
Answer : Option A
Explaination / Solution:
Every part of the wavefront at the slit acts as secondary sources because the incoming wavefront is parallel to the plane of the slit, these sources are in phase.
Q2. In the single slit diffraction, the screen is at a large distance as compared to slit width, the different rays from the slit would be
Answer : Option A
Explaination / Solution:
the screen on which the fringes are formed is at a large distance. The two or more paths from the slits to the screen were treated as parallel. Parallel paths from the slit are combined at a single point on the screen. This arrangement is often used since it gives more intensity than placing the screen far away.
Q3. n the single slit diffraction the screen is at a large distance compared to slit width and θ is the angle by which light has bent.If the size of slit is a.(given that n is not zero)
The condition for maxima is given by
Answer : Option D
Explaination / Solution:
Experimental observation indicates that the intensity has a central maximum at θ = 0 and other secondary maxima at θ = (n+1/2) λ/a, and has minima (zero intensity) at θ =nλ/a, n = ±1, ±2, ±3, ...
Q4. Which of the following phenomenon cannot be explained by diffraction?
Answer : Option A
Explaination / Solution:
No Explaination.
Q5. If two stars have an angular separation of Δθ and ‘a’ is the radius of the telescope aperture, then the angular resolution (for the stars to appear separate) is given by the expression
Answer : Option C
Explaination / Solution:
No Explaination.
Q6. If D and f are the objective diameter, and focal length, Minimum separation, , in the object plane of a compound microscope that can be resolved is given by
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. If ‘a’ is aperture size (i.e., slit or hole) and λ the wave length formula for Fresnel distance is
Answer : Option D
Explaination / Solution:
No Explaination.
Q8. For distances much greater than Fresnel distance ZF
Answer : Option B
Explaination / Solution:
No Explaination.
Q9. We say that a light wave is linearly polarized in y direction if
Answer : Option C
Explaination / Solution:
The displacement of electric field vector takes place along y axis for linearly polarised light along same direction though the direction of wave is at right angle to electric field vector.
Q10. If is the intensity after the first Polaroid the intensity emerging from the second Polaroid kept at an angle to the first is given by
Answer : Option A
Explaination / Solution:
As per malus law when a beam of completely plane polarised light i passed through the analyser the intensity of transmitted light varies directly as the square of cosine of angle between the plane of polariser and analyser.
