Consider the configuration of a system of four charges each of value (+q). Find the work done by external agent in changing the configuration of the system from (Fig. 3.44 A) to (Fig. 3.4B).
a. ,

Consider two configurations of a system of three particles of masses m , 2m and 3m . The work done by gravity in changing the configuration of the system from figure (i) to figure (ii) is

Four point charges q, q, q and – q are placed at the vertices of a square of side length a. The configuration is changed and the charge are positioned at the vertices of a rhombus of side length a with – q charge at the vertex where angle is 120^(@) . Find the work done by the external agent in changing the configuration.

Four charges + q, –q, + q and –q are put together on four corners of a square as shown in figure. The work done by external agent in slowly assembling this configuration is

If the amount of heat given to a system is 3 5 J and the amount of work done on the system is 15 J, then the change in internal energy of the system is

What is the potential energy of the charge and dipole system shown in (Fig. 3.93) ? .

Find the work done by some external force in moving a charge q=2muC from infinity to a point where electric potential is 10^4 V.

Find out potential at P and Q due to the two point mass system Find out work done by external agent in bringing unit mass from P to Q Also find work done by gravitational force. .

Fig shows three point charges +2q, -q and + 3q , What is the electric flux due to this configuration thorugh the surface S ?