A point charge of 100μC is placed at 3ˆi+4ˆj m. Find the electric field intensity due to this charge at a point located at 9ˆi+12ˆj m :
→r=(9−3)ˆi+(12−4)ˆj=6ˆi+8ˆj
or r=√62+82=10m
E=Kqr2
Electric field intensity due to point charge E=9×109×100×10−6102=9000Vm−1