A laser beam can be focused on an area equal to the square of its wavelength. A $$He-Ne$$ laser radiates energy at the rate of $$5mW$$ and its wavelength $$5000A0$$.The intensity of focused beam will be

Question

A laser beam can be focused on an area equal to the square of its wavelength. A $$He-Ne$$ laser radiates energy at the rate of $$5mW$$ and its wavelength  $$5000A0$$.The intensity of focused beam will be

Infinity Learn · Accepted Answer

$$A=$$λ$$2$$ Here $$A=$$ area    λ$$=wavelength$$ of laser beam  ⇒$$A=$$λ$$2=5$$×$$10$$−$$72=25$$×$$10$$−$$14m2$$ Now, $$I=PA$$ here  $$P=power$$    $$I=$$ Intensity of focussed beam ⇒$$I=PA=5$$×$$10$$−$$325$$×$$10$$−$$14=15$$×$$10+14$$×$$10$$−$$3=0.2$$×$$1011=2$$×$$1010Wm2$$

A laser beam can be focused on an area equal to the square of its wavelength. A He-Ne laser radiates energy at the rate of $5 m W$ and its wavelength $5000 A^{0} .$ The intensity of focused beam will be

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A laser beam can be focused on an area equal to the square of its wavelength. A He-Ne laser radiates energy at the rate of 5mW and its wavelength 5000A0.The intensity of focused beam will be

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A laser beam can be focused on an area equal to the square of its wavelength. A He-Ne laser radiates energy at the rate of $5 m W$ and its wavelength $5000 A^{0} .$ The intensity of focused beam will be