Question

Can electric flux be negative?

Answer 1

\[\Phi = E * A \cos120 = -2.025 \frac{ nm^2 }{ c }\]

Answer 2

That's what I get.

Answer 3

I don't know, I feel like I'm not fully understanding the concept hehe

Answer 4

yes

that looks good

Answer 5

ohh right I'm using magnitudes...

Answer 6

and cos(theta>90) = - negative

Answer 7

yes

Answer 8

Maxwell did this all on fluid-flow. so it's in or out. same with divergence, or convergence.

they're scalars but still numbers with signs.

Answer 9

ohhh

Answer 10

oH I'm getting it. Electric fields in this scenario are pointing inside which means the charge is negative?

Answer 11

so a sink!!

Answer 12

What about: a 2.0 cm x 3.0 cm rectangle lies in the xy-plane. What is the electric flux if
E= (100 i + 50 k) N/C?

--> I used the same process, I only calculated theta by arctan(50/100) = 27 ?

Answer 13

and magnitude of E = 112 n/c

for the flux= 0.06 nm^2/c ????

Answer 14

look for \(\vec E \bullet \hat z\)

Answer 15

what's z?

Answer 16

\(\hat k\)

Answer 17

ohhh I just realized lol I thought it was j

Answer 18

\(\Phi = \int \vec E \bullet \hat n \, da\)

that's the simplest formulation I know off hand

Answer 19

zero then

Answer 20

\(\vec E \bullet \hat n = <100,0,50>\bullet <0,0,1> = 50\)

Answer 21

So as you were doing originally, you then have \(\Phi = E * A\)