Advertisements
Advertisements
प्रश्न
Why upper surface of water contained in a beaker and above eye level appears silvery?
Advertisements
उत्तर
Critical angle for water is 49°. The rays of light entering the water from below, suffer refraction. If these rays strike the water-air surface at an angle which is greater than 48°, they get totally internally reflected. These rays on emerging out of the water, appear to come from the upper surface of the water, which in turn appears silvery.
संबंधित प्रश्न
Explain how the formation of a rainbow occurs.
A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence (∠i). He then measures the corresponding values of the angle of refraction (∠r) and the angle of emergence (∠e) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be
(A) ∠i > ∠r > ∠e
(B) ∠i = ∠e > ∠r
(C) ∠i < ∠r < ∠e
(D) ∠i = ∠e < ∠r
Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.
The speed of light in glass is 2 × 105 km/s. What is the refractive index of glass?
Complete Fig. 4.32 to show the path of the ray of single colour as it enters the prism and emerges out of it. Mark the angles wherever necessary.
A ray of light passes from air to water. In fig. 39, which of the ray A, B, C and D is the correct refracted ray?
The figure shows two prisms A and B. A monochromatic ray of light PO is incident at the face of the prism A. Complete the diagram to show the path of the ray till it emerges out of the prism B.
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.
What should be the rate of the speed of light through the liquid to the speed through the glass so that there is no refraction of light at the boundaries of the glass block when the system is illuminated by the light of one colour?
The path of a ray of light coming from air passing through a rectangular glass slab traced by four students are shown as A, B, C and D in the figure. Which one of them is correct?
 |
 |
 |
 |
| A | B | C | D |
Consider these indices of refraction: glass: 1.52; air: 1.0003; water: 1.333. Based on the refractive indices of three materials, arrange the speed of light through them in decreasing order.
