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A laser beam of pluse power 10^(12) watt...

A laser beam of pluse power `10^(12)` watt is focussed on an object are `10^(-4) cm^(2)`. The energy flux in `watt//cm^(2)` at the point of focus is

A

`10^(20)`

B

`10^(16)`

C

`10^(8)`

D

`10^(4)`

Text Solution

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The correct Answer is:
B
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Knowledge Check

  • A beam of unpolarised light having flux 10^(-2) watt falls normally on a polariser of cross sectional area 3 xx 10^(-4) m^(2) . The polariser rotates with an angular frequency of pi rad/s. The energy of liggt passing through the polariser per revolution will be

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    D
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  • A laser beam of 10mW power and wavelength 700nm has aperture of 3mm . If it is focused by a lens of focal length 5cm , the intensity of image is

    A
    (a) `1.56xx10^7W//m^2`
    B
    (b) `3xx10^6W//m^2`
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    D
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