A 25-W incandescent light bulb radiates uniformly in all directions.(a) Calculate the average intensity 2.1 m from the bulb.lavg @ 2.1 m =W/m²(b) What is the average intensity 4.5 m from the bulb?lavg @ 4.5 m =W/m² EM waves, like all other waves, are generated a source. The power of a source measures the rate that it radiates EM energy. The energy spreadsoutward as the wave carries it away from the source so the amount crossing a given area decreases with distance.The intensity at a given point measures the rate per unit areathat EM energy is being transported to that point (i.e. received).Intensity = Source Power/Surface AreaThe surface area takes into account the specific details of howenergy spreads outward as it radiates away from the source.A light source that radiates uniformly in all directions like theone shown in the figure is called isotropic or omni-directional.The energy is spread uniformly across spherical surfaces thatare centered on the source so the intensity, , a distance, d,from an isotropic source that with power, P, is given by:Il=P4zd²ObservationPointSurface Area = 4nd²

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Answered: A 25-W incandescent light bulb radiates…

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A 25-W incandescent light bulb radiates uniformly in all directions. (a) Calculate the average intensity 2.1 m from the bulb. lavg @ 2.1 m = W/m² (b) What is the average intensity 4.5 m from the bulb? lavg @ 4.5 m = W/m²