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4 xx 10^(10) electrons are removed from a neutral metal sphere of diameter 20 cm placed in air. The magnitude of the electric field (in N C^(-1)) at a distance of 20 cm from its centre is |
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Answer» 5760 Number of electrons (N) `= 4XX10^(10)` Diameter of sphere (D) = 20 cm Radius of sphere (r ) `= (20)/(2)=10 cm = 0.01m` According to question, `E_("outside")=(q)/(4pi epsilon_(0)r^(2))` `= ("ne")/(4pi epsilon_(0)r^(2))` Here, `r=20xx10^(-2)m` `= (4xx10^(10)xx1.6xx10^(-19)xx9xx10^(9))/((20xx10^(-2))^(2))` `= (4xx1.6xx9)/(20xx20xx10^(-4))` `= (4xx16xx9xx10^(4))/(20xx20)` `= 16xx9xx10^(2)` `= 144xx10^(2)=1440 NC^(-1)` |
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