Question

Two point particles, one with charge +8 x 10^-9C and the other with charge -2 x 10^-9C are separated by 4m. The electric field in N/C midway between them is:
(a) 9 x 10^9
(b) 13,500
(c) 36 x 10^-9
(d) 22.5​

Answer 1

Answer:

Explanation:hope it helps.

Answer 2

Answer:

Option D Electric field at the midpoint of the charges is 22.5N/C.

Explanation:

Electric field for a given charge is explained by the relation,

$E=\frac{KQ}{r^{2} }$

Where E is the electric field, Q is the given charge and r is the distance between the given point and the given charge.

We are given as,

Q₁=$+8*10^{-9}$C

Q₂=$-2*10^{-9}$C

and the separation between the charges is 4m.

So there midpoint is at distance of 2m from each charge.

Electric field at the midpoint due to Q₁,

$E_{1} =\frac{K*8*10^{-9} }{2^{2} } =\frac{9*10^{9} *8*10^{-9} }{2^{2} }\\E_{1} =18 V/m$

Electric field at the midpoint due to Q₂,

$E_{2} =\frac{K*(-2*10^{-9} )}{2^{2} } =\frac{9*10^{9} *(-2*10^{-9}) }{2^{2} }\\E_{2} =-4.5 V/m$

Resultant electric field at midpoint,

$E_{res} =E_{1}- E_{2} \\E_{res} =18-(-4.5)\\E_{res} =22.5\ N/C$

Hence the electric field midway between the charges is 22.5N/C.