Aparticle with a charge of 3.00 elementary charges moves through a potential difference of 4.50 volts. what is the change in electrical potential energy of the particle?
(1)1.07 × 10 19ev
(2)2.16 × 10 18ev
(3)1.50 ev
(4)13.5 ev

The
the relationship between elementary charge, potential difference and electrical potential energy is given by 
   E= qV
E:  lectrical potential energy
q:   elementary charge
V:   potential difference

but we have  e=abs val(q)=3 
so we have E= qV=3ex4.5V=13.5 eV

the answer is (4)13.5 eV

Alinear relationship would look like a straight line on the graph. it could have a positive negative or 0 slope. so it could be a line potentially going in any direction but it must be perfectly straight.