Gauss Law (1)

Gauss Law (1) - cancel each other out and that is why the...

This preview shows pages 1–18. Sign up to view the full content.

Flux and Gauss' Law Ch 22 AP Physics C

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Background Gauss’ Law is part of the key to using symmetry considerations to simplify E- Field calculations (remember section 21.5 when we integrated to solve for E of a ring of charge, line of charge etc.) In chapter 21 we asked: What is the E-field due to a known charge distribution? In chapter 22 we will ask: What is the charge distribution if we know E ?
The box may enclose a charge, by placing a test charge and observing F, we know E. It is only necessary to do this at the surface of the shape.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Flux Flux, in this case Electric Flux, is the amount of (electric) field passing through a specified area. Think of water flowing in a pipe (flux comes from the Latin for “flow”)
Pictures of outward (+) flux and inward (-) flux

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Situations where the total flux equals zero
The E-field decreases at 1/r 2 while the area increases at r 2 and that increase and decrease

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: cancel each other out and that is why the size of the surface enclosing Q does not matter. Flux • Symbol Ф E • Unit Nm 2 /C • Equation: ∫ ⋅ = Φ = ⋅ = Φ A d E EA A E E E θ cos What we can conclude about Ф 1. Ф is proportional to q 2. Whether Ф is inward or outward depends on the q inside the surface 3. A q outside the surface offers zero Ф because Ф in = Ф out Ф = 0 through triangular prism below. See board for the proof E = 500 N/C 40 cm 50 cm 30 cm 40 cm Gauss’ Law • The total electric flux through any closed surface is proportional to the net electric charge inside the surface Gauss’ Law cos ε θ enclosed enclosed E Q dA E dA E A d E Q A d E = = = ⋅ = ⋅ = Φ ∫ ∫ ∫ ∫ ⊥ Point Charge Uniformly charge insulator at a varying r Line of Charge Sheet of Charge...
View Full Document

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern