Answer:
option d) 12.0 V
Step-by-step explanation:
Data provided in the question:
Potential difference due to a single charge (+Q), E = 3.0 V
Now,
The Electric potential for the system of charges is given as:
![E=(1)/(4\pi \epsilon_o)[\Sigma(Q)/(r)]](https://img.qammunity.org/2020/formulas/physics/high-school/s5slpu5vixmvryoht0y6a1bcxqbidc38ar.png)
given for single charge, E = 3.0 V =
.......(1)
so thus, for 4 charges, we have
...............(2)
from 1 and 2 we have
E = 4 × 3.0 V = 12 V
Hence, option d) 12 V is the correct answer.