Home
Class 12
PHYSICS
A laser beam of power 20W incident norma...

A laser beam of power 20W incident normally on a surface. if 25% light is absorbed and rest reflected find magnitude of force experienced by the surface.

A

`1.16xx10^(-7)N`

B

`2.32xx10^(-3)N`

C

`4.12xx10^(-2)N`

D

`5.21xx10^(-7)N`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

What is the force exerted by a Light Beam On a Surface ?

A parallel beam of light is incident normally on a plane surface absorbing 40% of the light and reflecting the rest. If the incident beam carries 60 W of power, the force exerted by it on the surface is

A beam of white light is incident normally on a plane surface absorbing (70%) of the light and reflecting the rest. If the incident beam carries 10 W of power , find the force exerted by it on the surface .

A beam of white light is incident normaly on a plane surface absorbing 70% of the light and reflecting the rest. If the incident beam carries 10 w of power, find the force exerated by it on the surface.

Light of intensity 50W//m^(2) is incident on a arae of 1m^(2) in such a way that 25% of light is reflected back. Find the force exerted by light on surface if light incident perpendicularly

A "50 W m"^(-2) energy density of sunlight is incident normally on the surface of a solar panel. Some part of incident energy (25%) is reflected from the surface and the rest is absorbed. The force exerted on 1m^(2) surface area will be close to (c=3xx10^(8)ms^(-1))

A parallel beam of light is incident normally on the flat surface of a hemisphere of radius 6 cm and refractive index 1.5 , placed in air as shown in figure (i). Assume paraxial ray approxiamtion. .

A glass prism is immeresed in water as shown in the figure. When a beam of light incident is incident normally on the face ab, it is internally reflected at the face ad. If the refractive index of glass is 1.5 and that of water is 4//3 , then

A parallel beam of light of intensity I is incident on a glass plate. 25% of light is reflected in any reflection by upper surface and 50% of light is reflected by any reflection from lower surface. Rest is refracted The ratio of maximum to minimum intensity in interference region of reflected rays is

Light with an energy flux of 18 W cm^(-2) falls on a non-reflecting surface at normal incidence. If the surface at normal incidence. If the surface has an area of 20 cm^(2) , find the average force exerted on the surface during a span of 30 min.

ALLEN-TEST PAPER 4-PHYSICS
  1. If veca=2hati+6hatj +3hatk, vecb=hati+lamdahatj+muhatk if veca xxvecb...

    Text Solution

    |

  2. A plate of mass 10 gm is in equillibrium in air due to the force exter...

    Text Solution

    |

  3. A laser beam of power 20W incident normally on a surface. if 25% light...

    Text Solution

    |

  4. How many photons per second does a one watt bulb emit if its efficienc...

    Text Solution

    |

  5. A hydrogen atom moving at a speed v absorbs a photon of wavelength 122...

    Text Solution

    |

  6. When a metallic surface is illuminated by a monochromatic light of lam...

    Text Solution

    |

  7. Photoelectric emission is observed from a metallic surface for frequen...

    Text Solution

    |

  8. Electric field associated with a light wave is given E= E(0) sin [1.57...

    Text Solution

    |

  9. When a monochromatic point source of light is at a distance of 0.2 m...

    Text Solution

    |

  10. Light of wavelength 200 nm incident on a metal surface of threshold wa...

    Text Solution

    |

  11. For a photoelectric experiment graph between kinetic energy of fastest...

    Text Solution

    |

  12. If y=5 (sin 100^(@)cos 27^(@) +cos 100^(@)sin 27^(@)) the value of y i...

    Text Solution

    |

  13. Given that =(10)/(sin x+ sqrt3 cos x) the minimum positive value of y ...

    Text Solution

    |

  14. Differentiation of cos (sqrt(x)) with respect to x is

    Text Solution

    |

  15. Given a function y=x^(2)-2sqrt(x). What is rate of change in y with re...

    Text Solution

    |

  16. If y=(x^(2))/((x+1))"then"(dy)/(dx)"is":-

    Text Solution

    |

  17. If y=log(e)x+sinx+e^(x)" then "(dy)/(dx) is

    Text Solution

    |

  18. If y=x^(3)cosx" then "(dy)/(dx)=……………………

    Text Solution

    |

  19. If the velocity of a paraticle moving along x-axis is given as v=(4t^(...

    Text Solution

    |

  20. (5)Value of underset(0)overset(2)int3x^(2)dx+underset(0)overset(pi/2)i...

    Text Solution

    |