Advertisements
Advertisements
प्रश्न
A spherical marble, of refractive index 1.5 and curvature 1.5 cm, contains a tiny air bubble at its centre. Where will it appear when seen from outside?
पर्याय
1 cm inside
at the centre
`5/3` cm inside
2 cm inside
Advertisements
उत्तर
`bb(5/3)` cm inside
Explanation:
The refractive index of the marble is 1.5.
One can see the image formed due to the reflection in the spheres.
In order to determine the distance where the image will form, use the lens maker formula.
Hence, `mu_1/v - mu_2/u = (mu_2 - mu_1)/"R"`
Where, refractive index of air = 1, refractive index of glass = 1.5, Radius of the curvature = 1.5 cm
Substituting the values, we get,
`therefore 1/v - 1.5/0.75 = (1 - 1.5)/1.5`
`therefore 1/v - 2 = - 0.5/1.5`
`therefore 1/v - 2 = - 1/3`
`therefore 1/v = - 1/3 + 2`
`therefore 1/v = (- 1 + 6)/3`
`therefore 1/v = 5/3`
Therefore, the tiny bubble will be seen 5/3 cm inside when we see it from the outside.
APPEARS IN
संबंधित प्रश्न
Name the factors affecting the critical angle for the pair of media.
The figure shows a ray of light falling normally on the face AB of an equilateral glass prism having refractive index`3/2`, placed in water of refractive index `4/3`.Will this ray suffer total internal reflection on striking the face AC? Justify your answer.
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is ______.
Name two factors which affect the critical angle for a given pair of media. State how do the factors affect it.
Solve the previous problem if the paperweight is inverted at its place so that the spherical surface touches the paper.
Define critical angle for a given medium.
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
If a light ray does not undergo, refraction at the boundary between two media, the angle of incidence is:
(a) A ray of monochromatic light enters glass PQRS as shown in the fig. Complete the path of ray till it emerges from the glass. (Critical angle of glass is 420).
(b) Draw diagram of a prism periscope.
(c) What are the advantages of total internal reflecting prism over plane mirror?
How does a ray of light bend when it travels from denser to rarer medium.
Can light be ‘piped’ like sound in a doctor’s stethoscope?
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
What is meant by the statement, ‘the critical angle for diamond is 24°’?
What is meant by the term ‘critical angle’?
Draw a diagram, properly labelled, to illustrate the use of a total reflecting prism (a right-angled isosceles prism) to turn a ray of light through 180°. Name an instrument in which this device is used.
The resultant `vec"R"` of `vec"P"` and `vec"Q"` is perpendicular to `vec"P"`. Also `|vec"P"|=|vec"R"|`. The angle between `vec"P"` and `vec"Q"` is ______.
[tan 45° = 1]
For the same angle of incidence, the angle of refraction in four media A, B, C and D are 25°, 30°, 35° and 40° respectively. The speed of light is least in medium ______.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
For a ray of light, the critical angle is minimum when it travels from ______.
Optical fibre communication uses the principle of ______.
The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
What are the conditions to achieve total internal reflection?
A ray of light incident at an angle θ on a refracting face of a prism emerges from the other face normally. If the angle of the prism is 5° and the prism is made of a material of refractive index 1.5, the angle of incidence is ______.
A ray of light passes from vacuum into a medium of refractive index µ, the angle of incidence is found to be twice the angle of refraction. Then the angle of incidence is ______.
A given ray of light suffers minimum deviation in an equilateral prism P. Additional prism Q and R of identical shape and of the same material as P are now added as shown in the figure. The ray will now suffer ______.
- Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
- Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.
The diagram below shows a fish in the tank and its image seen on the surface of the water.
Name the phenomenon responsible for the formation of this image.
