
A spherical shell has a uniform positive charge density on its surface. (There are no other charges around.)
What is the electric field inside the sphere?
- E=0 everywhere inside
- E is non-zero everywhere in the sphere
- E=0 only that the very center, but non-zero elsewhere inside the sphere.
- Not enough information given
- Exam 1 on Wednesday, October 3rd (BCH 101)
- Next to BPS (Wilson side)
- 7pm-9pm
- Arrive on time!
- Put one seat between you and the next person
- I will provide a formula sheet (posted on Slack already)
- You can bring one-side of a sheet of paper with your own notes.
- 5 questions - True/False, Essay, Code, Graphing, Short Calculations
What's on Exam 1?
- Identify whether conceptual statements about E, V, ρ, and/or numerical integration are true or false.
- Sketch and discuss delta functions in relation to charge density, ρ
- Explain the process for using a computational alogrithm for predicting E and write the necessary code to illustrate how it works for a given example
- Calculate the electric field, E, inside and outside a continuous distribution of charge and sketch the results
- Calculate the electric potential, V, for a specific charge distribution and discuss what happens in limiting cases
We are trying to compute the the electric potential V(r) for a line of charge at the location ⟨x,0,z⟩. What is |R| in this case?
- x
- z
- √x2+z2
- Something else
We derived the potential for this short rod to be
V(x,z)=λ4πε0log[L+z+√x2+(L+z)2L−z+√x2+(L−z)2]
The associated electric field at ⟨x,0,z⟩ location can have the following components:
- only x
- only y
- only z
- x, y, and z
- Something else

A spherical shell has a uniform positive charge density on its surface. (There are no other charges around.)
What is the electric field inside the sphere?
- E=0 everywhere inside
- E is non-zero everywhere in the sphere
- E=0 only that the very center, but non-zero elsewhere inside the sphere.
- Not enough information given
We derived the electric potential outside (r>R) the charged shell to be
V(r)=14πε0qr
What is it for r<R?
- Zero
- Constant
- It changes but I don't know how yet
- Something else

Could this be a plot of |E(r)|? Or V(r)? (for SOME physical situation?)
- Could be E(r), or V(r)
- Could be E(r), but can't be V(r)
- Can't be E(r), could be V(r)
- Can't be either
- ???
A spherical shell has a uniform positive charge density on its surface. (There are no other charges around.)
What is the electric field inside the sphere?
E=0 everywhere inside
E is non-zero everywhere in the sphere
E=0 only that the very center, but non-zero elsewhere inside the sphere.
Not enough information given
Correct Answer: A