The potential difference and the electric field - please check my answer

[medlyra]

Homework Statement

The potential difference between the ends of a 2 meter stick that is parallel to a uniform electric field is 400V. The magnitude of the electric field is:

Homework Equations

V = E.d

The Attempt at a Solution

E = v/d = 200 v/m
The right answer
is 800 v/m, my understanding is U= qV= Fd therefore qV= Eqd and E = V/d so I don't know how they came up with this answer (800v/m)

 

[Spinnor]

Looks right to me.