Wave Optics - Online Test
Q1. Monochromatic light of wavelength 589 nm is incident from air on a water surface. What is the wavelength and speed of reflected light?
Answer : Option A
Explaination / Solution:
No Explaination.
Q2. Monochromatic light of wavelength 589 nm is incident from air on a water surface. What is the wavelength and speed of refracted light? Refractive index of water is 1.33.
Answer : Option D
Explaination / Solution:
No Explaination.
Q3. Shape of the wave front of light diverging from a point source is
Answer : Option B
Explaination / Solution:
When light diverges from a point source it moves in the form of diverging spherical wavefront.
Q4. Shape of the wave front of light emerging out of a convex lens when a point source is placed at its focus.
Answer : Option D
Explaination / Solution:
The rays of light becomes parallel after passing through a convex lens if the object is placed at focus. The shape of wavefront is plane as wavefront is perpendicular to rays.
Q5. Shape of the wave front of portion of the wave front of light from a distant star intercepted by the Earth
Answer : Option A
Explaination / Solution:
Stars are very far away from earth.Near the star the shape is spherical but by the time its light reaches earth the portion of the wavefront is plane due to increase in radius.
Q6. The refractive index of glass is 1.5. What is the speed of light in glass? (Speed of light in vacuum is 3.0)
Answer : Option D
Explaination / Solution:
No Explaination.
Q7. The refractive index of glass is 1.5 which of the two colors red and violet travels slower in a glass prism?
Answer : Option A
Explaination / Solution:
The refractive index and wavelength are inversly related.
The wavelength of violet is least in the visible region so it bends the most.
Q8. In a Young’s double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment
Answer : Option D
Explaination / Solution:
No Explaination.
Q9. In Young’s double-slit experiment using monochromatic light of wavelength l, the intensity of light at a point on the screen where path difference is λ, is K units. What is the intensity of light at a point where path difference is λ /3?
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes in a Young’s double-slit experiment. Find the distance of the third bright fringe on the screen from the central maximum for wavelength 650 nm.
Answer : Option B
Explaination / Solution:
No Explaination.
