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Intensity of point-like source at 1000 m is I. it is changed to 16I, then required distand will be |
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Answer» 250 m `I=(phi)/(4 PI r^2)` `therefore I prop (1)/(r^2)` `therefore (I)/(I.)=((r.)/(r))^2` `therefore (I)/(16 I)=(r.^2)/((1000 m)^2)` `therefore r.^2=((1000 m)^2)/(16)` `therefore r.=(1000m)/(4)` `therefore r.=250` m |
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