Question

What is the strength of the electric field ep 0.90 mm from a proton?

Answer 1

The electric field strength is inversely related to the square of the distance.so the strength of the electric field is given by

`E=(1)/(4\pi \epsilon _(0)  ) (q)/(r^(2) ) = (k q)/(r^(2) )`

Here,
`(1)/(4\pi \epsilon _(0)  ) = k` is constant depend upon medium and its value is
`9.0 *10^(9) \ N m^2/C^2` and q is charge and r is the distance.

Given
`r = 0.90 mm = 9.0 * 10^(-4) m` and we know the charge of proton,
`q = 1.6* 10^(-19) \ C`.

Therefore,

`E=(9.0 *10^(9) \ N m^2/C^2 *1.6* 10^(-19) \ C  )/((9.0 * 10^(-4) m)^2) = 0.177 * 10^(-2) \ N/C \\\\  E= 1.77 * 10^(-3)  N/C`