Advertisements
Advertisements
Question
The refractive indices of water and diamond are `4/3` and 2.42 respectively. Find the speed of light in water and diamond. (c = 3x108 m/s)
Advertisements
Solution
`""^amu_w = 4/3`
`""^amu_d =2.42`
`""^amu_w = 4/3 = V_a/V_w`
`:. V_w = (3 xx10^8)/(4/3) = 3 xx 10^8 xx 3/4 = 2.25 xx 10^8` m/c
`""^amu_d = 2.42 = V_a/V_d = (3xx10^8)/V_d`
`V_d = (3xx10^8)/2.42 = 1.23 xx 10^8` m/s
APPEARS IN
RELATED QUESTIONS
On the basis of Huygens' wave theory of light prove that velocity of light in a rarer medium is greater than velocity of light in a denser medium.
Using Huygens's construction of secondary wavelets explain how a diffraction pattern is obtained on a screen due to a narrow slit on which a monochromatic beam of light is incident normally.
Explain the construction of plane wavefront using Huygens’ principle.
What is the shape of the wavefront in the following case?
Light emerging out of a convex lens when a point source is placed at its focus.
What is the shape of the wavefront in the following case?
The portion of the wavefront of light from a distant star was intercepted by the Earth.
State Huygen’s principle.
Consider a plane wave front incident on a thin convex lens. Draw a proper diagram to show how the incident wave front traverses through the lens and after refraction focusses on the focal point of the lens, giving the shape of the emergent wave front.
Huygens' principle of secondary wavelets may be used to
(a) find the velocity of light in vacuum
(b) explain the particle behaviour of light
(c) find the new position of a wavefront
(d) explain Snell's Law
Light waves travel in vacuum along the X-axis. Which of the following may represent the wave fronts?
Answer the following question.
Define the term wavefront. Using Huygen's wave theory, verify the law of reflection.
Define a wavefront. Using 'Huygens' principle, draw the shape of a refracted wavefront, when a plane wave is incident on a convex lens.
A plane wave front AB propagating from denser medium (1) into a rarer medium (2) is incident on the surface P1P2 separating the two media as shown in fig.
Using Huygen’s principle, draw the secondary wavelets and obtain the refracted wave front in the diagram.

According to Huygen's construction, relation between old and new wavefront is ______.
Relation between ray and wavefront is ______.
What is the geometrical shape of the wavefront for:
- Light diverging from a point source?
- The pattern of wavefront of the light from a distant star intercepted by earth?
Answer the following question briefly and to the point:
What is the phase difference between any two points lying on the same wavefront?
The inverse square law of intensity is valid for a
Wavefront means
Figure shows a standard two slit arrangement with slits S1, S2, P1, P2 are the two minima points on either side of P (Figure). At P2 on the screen, there is a hole and behind P2 is a second 2-slit arrangement with slits S3, S4 and a second screen behind them.

Is Huygen’s principle valid for longitudinal sound waves?
According to Huygens’s principle, the amplitude of secondary wavelets is ______.
How is a wavefront different from a ray?
What type of wavefronts are associated with a source infinity?
Using Huygen’s wave theory of light, show that the angle of incidence is equal to the angle of reflection. Draw a neat and labelled diagram.
When can a small portion of a spherical wave be considered as a plane?
Which book by Christiaan Huygens is cited as an important work?
What improved devices did Christiaan Huygens design?
What did Christiaan Huygens discover about Saturn?
What happens when a small stone is dropped on a calm pool of water?
How does every point on the surface of a calm pool respond after a small stone is dropped into it?
At any instant, where is the disturbance maximum on the surface of the water?
Why are all points on a circular ring of the water wave oscillating in phase?
What is a locus of points which oscillate in phase called?
What kind of construction is Huygens' principle essentially?
In Huygens' principle, what does each point of the wavefront act as?
How do wavelets emanating from points on a wavefront spread?
What are the wavelets emanating from points on a wavefront called?
What gives the new position of a wavefront at a later time in Huygens' construction?
What role does each point of a spherical wavefront play in constructing its later position?
What shortcoming does Huygens' model have?
What did Huygens argue about the amplitude of secondary wavelets?
How is Huygens' adhoc assumption about the backwave assessed?
