Question 1 Answer each of the questions with Positive, Negative or Zero a) The change in potential energy of the system in moving a negative charge from A to B) b) The change in potential energy of the system in moving a positive charge from C to A

Question 1

Answer each of the questions with Positive, Negative or Zero

a) The change in potential energy of the system in moving a negative charge from A to B)

b) The change in potential energy of the system in moving a positive charge from C to A.

c) The work done by the field in moving a negative charge from C to A.

d) The work done by an external force in moving a positive charge from D to C. If it starts and ends at rest.

e) The change in potential moving a negative charge from B to C.

Answer Here:        C,D

a) [ Select ]

,A    Numerical value are in volts

b) [Select]

c) [ Select ]

d) [Select ]

e) [Select]

Question 2  

An Infinite conductive plate has charge density σ₁ when it is brought in from infinity and placed between, x=0 and x=1m (It is 1m thick, just a small portion b picture below). A second infinite conductive plate has charge density σ₂ when It is brought in from infinity and placed between x=5 and x=6 m. Additional information below.

a) Find the electric field at the following locations:

(i) (-3,0)                (ii) (-1,3)               (iii) (0.5, 0)           (iv) (4,0)               (v) (5.5, 0)           (vi) (9,0)

b) Find the electric potential at the following locations,

(i) (-3,0)                (ii) (-1,3)               (iii) (0.5, 0)           (iv) (4,0)               (v) (5.5, 0)           (vi) (9,0)

Additional Information:

Σ₁ = 4*10^-10 c/m²

Σ₂ = -6*10^-10 c/m²

V = 0 at x=0                                    

                                                                     -5          -3            -1              0        2              4              6              8              x(m)

Question 3

Three charge distributions are shown:

1) A thin, insulating spherical shell, radius 3a, with a charge -3Q uniformly distributed over its surface (Q is positive, units are C)

2) A circular arc that spans 90⁰ as shown. The curve has a non-uniform charge density, lc

= -(Q/a)sin ?

(a is positive, units are m and ? is measured from the –x axis, as shown).

3) A thin, straight rod of uniform charge density carries a total charge +3Q and extends from x= -2a to x= 2a, as shown, at y=2a.

a) Find the work done by the field in moving a charge, +Q, from the origin to infinity. The charge starts and ends at rest.

b) Specifically state if the work calculated in part a is positive, negative, or Zero.

Your answer should be in terms of Q a, and our usual constants (€₀ and/or K).

                                                                                             Y

                                                                     3a

                                                                     2a     

                                                                                                                                                                                                X

-3a          -2a                          -a                            0              a              2a                           3a