Right, as you mentioned in the comments, you find
by plugging in the different values of
.
For
, we have



Similarly, for
, you get



Explanation:
Given that,
Electric field = 5750 N/C
Charge 
Distance = 5.50 cm
(a). When the charge is moved in the positive x- direction
We need to calculate the change in electric potential energy
Using formula of electric potential energy



Put the value into the formula


The change in electric potential energy is 
(b). When the charge is moved in the negative x- direction
We need to calculate the change in electric potential energy
Using formula of electric potential energy



Put the value into the formula


The change in electric potential energy is 
Hence, This is the required solution.
Answer : Capacitors
Explanation : Capacitors are normally placed on transmission or distribution lines when to reduce inductive reactance.
This is because it enhances electromechanical and voltage stability , limit voltage dips at network nodes and reduces the power loss.
So, we can say that inductive reactance normally replace by the capacitors.
= Heat released to cold reservoir
= Heat released to hot reservoir
= maximum amount of work
= temperature of cold reservoir
= temperature of hot reservoir
we know that

eq-1
maximum work is given as
=
- 
using eq-1
=
- 