AAMC physics question pack 24

So, the question asks which of the following changes to the circuit will decrease the electric field between teh electrodes by the greatest amount?

A. Increasing L by a factor of 2

B. Decreasing L by a factor of 2

C. Increasing R by a factor of 2

D. Decreasing R by a factor of 2.


I got the answer correct but when i read the solution i dont know where does E= (V-IR)/ L comes from. I only know E= V/L or at least i can substitute ohm's law E= IR/L. I dont see that V-IR coming from. lol...

AAMC physics question pack 24