Home
Class 12
PHYSICS
A ray of light travelling through rarer ...

A ray of light travelling through rarer medium is incident at very small angle i on a glass slab and after refraction its velocity is reduced by 20%. The angle of deviation

A

`(i)/(8)`

B

`(i)/(5)`

C

`(i)/(2)`

D

`(4i)/(5)`

Text Solution

Verified by Experts

The correct Answer is:
B
`V_(m)=80%" of "V_(a)=0.8V_(a)`
`:.mu=(sini)/(sinr)=(V_(a))/(V_(m))=(V_(a))/(0.8V_(a))`
`:.(i)/(r)=1.25" "i.e.,i=1.25r`
Thus, `delta=i-r`
`=i-(i)/(1.25)=(1.25i-i)/(1.25)`
`=i((0.25)/(1.25))=(i)/(5)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • MHT-CET 2016

    NIKITA PUBLICATION|Exercise INTERFERENCE AND DIFFRACTION|3 Videos

  • MHT-CET 2016

    NIKITA PUBLICATION|Exercise ELECTROSTATICS|3 Videos

  • MHT-CET 2016

    NIKITA PUBLICATION|Exercise KINETIC THEORY OF GASES & RADIATION|3 Videos

  • MH-CET - 2017

    NIKITA PUBLICATION|Exercise CUMMUNICATION SYSTEMS|1 Videos

  • OSCILLATIONS

    NIKITA PUBLICATION|Exercise MCQ|493 Videos

Similar Questions

Explore conceptually related problems

A ray of light travelling in air is incident on the surface of glass slab at an angle of 40^(@) . If the ray is deviated through 18^(@) , determine critical angle for the glass-air interface.

A ray of light travelling in air is incident at 45^(@) on a medium of refractive index sqrt(2) . The angle of refractive in the medium is

Knowledge Check

  • A ray of light travelling through rarar medium is incident at very small angle i on a glass slab and after refraction its velocity is reduced by 20\% . The angle of deviation is

    A
    `i/8`
    B
    `i/5`
    C
    `i/2`
    D
    `(4i)/5`

  • Light is incident at an angle i on a glass slab. If the reflected ray is completely polarised , then the angle of refraction is

    A
    `180^@-i`
    B
    `90^(@)+i`
    C
    `i`
    D
    `90^(@)-i`

  • Light is incident at an angle i on a glass slab. The reflected ray is completely polarished . The angle of refraction is

    A
    `90^(@) - i`
    B
    `180^(@) - i`
    C
    `90^(@) + i`
    D
    `i`

    • Similar Questions

    Explore conceptually related problems

    The critical angle between a certain transparent medium and air is phi . A ray of light travelling through air enters the medium at an angle of incidence equal to its Brewster angle theta. Therefore, the angle of refraction is

    A ray of light travelling from air to glass is deviated by an angle of 24^(@) . If the reflected and refracted rays are at right angles then the angles of incidence is

    A ray of light is incident on a glass slab at an angle of 45^(@) . If refractive index of glass be 1.6, what is the angle of refraction ?

    The ray of light travels from raer medium to denser medium of refractive index mu . The angle of incidence of twice the angle of refraction. The angle of incidence is given by

    A ray of lighyt is incident at an angle I on a glass slab of refractive index mu . The angle between reflected and refracted light is 90^@ Then the relationship between I and mu is

    Home
    Profile