Answer:
The potential across the plates is 5.25 V
Step-by-step explanation:
Let us assume that the Electric field is E; Force is F; Unit charge is q, the Electric potential is V and distance is d.
Here E = 150 v/m and d = 3.5 cm = 0.035 m
Now we know that,
Electric Field E
----- [1]
----- [2]

So,


Thus, The potential across the plates is 5.25 V