Why is the answer C for electric field and potential?

[delsoo]

Homework Statement

hi, all, can anyone explain why the ans is C for this question?
http://i.imgur.com/yGyu5G3.jpg

for the second question? shoudnt the ans is D ?
http://i.imgur.com/R4Gvjoz.jpg

Homework Equations

The Attempt at a Solution

 

[rude man]

For first question:
E = -grad V = -∂V/∂x i
where i is unit vector in direction of P→Q.

So now do you think C is correct? Why or why not?

For second question : I agree with you!

 

[cheah10]

For second question: I agree with you guys too!

 

[rude man]

For first question:
E = -grad V = -∂V/∂x i
where i is unit vector in direction of P→Q.

So now do you think C is correct? Why or why not?

For second question : I agree with you!

E, being a vector, I should have written in bold, and is hereby so corrected.

 

[Simon Bridge]

@delsoo: how did you get on with this in the end?