Electric Field Due to a Charged Sphere A conducting sphere of radius 10 cm has an unknown charge. If the electric field 20 cm from the centre of the sphere is `1.5xx10^(3)` N/C and points radially radially inwards, the what is the net charge on the sphere ?

Explanation

Let the value of unknown charge be q.
Electric field ar 20 cm away, `E=1.5xx10^(3)` N/C

From the formula, electric field,
`E=(1)/(4piepsilon_(0))*(q)/(r^(2))`
`1.5xx10^(3)=(9xx10^(9)xxq)/((20xx10^(-2))^(2))`
`q=(1.5xx10^(3)xx20xx20xx10^(-4))/(9xx10^(9))`
`=6.67xx10^(-9)C`
As, the electric field is radially inwards which shows that the nature of unknown charge q is negative.