# (1) A +2C charge is located at the point (x,y) =(5cm,0cm) and a +1C charge is at origin .The +2C charge is moved to the point (3cm,4cm).The force on the +1C charge(a) Has changed in magnitude only(b) Has changed neither in magnitude nor direction(c) Has changed in direction only(d) Has changed in both magnitude and directionPlease show me the solution !!

Apoorva Arora IIT Roorkee
9 years ago

The +1 C charge is fixed at the origin O. When the charge +2C is at A. The force between the two charges is$\frac{Kq_{1}q_{2}}{r^{2}}$ i.e$\frac{2K}{5^{2}}$and since the force is a central force, it acts along the line joining the two charges i.e. it will be along OA facing away from A.
Now, when the charge +2C is shifted to the new position B, the distance between O and B is still 5 units and therefore, the force remains the same. But, now the force acts along OB facing away from B. Hence, only the direction changes, the force remains the same because r remains same.

Thanks and Regards
Apoorva Arora
IIT Roorkee