Find electric field at point (2, 1) due to an electron placed at the origin
For a negative source charge, the electric field at point P points radially inwards.
In pur case Q =−1.6×10−19 C
→r=(2^i+^j)∴|→r|=√(2)2+(1)2=√5→E=Q→r4πε0r3=−1.6×10−19×9×109(√5)3(2^i+^j)→E=1.44×10−95√5(−2^i−^j)