Unformatted text preview: Physics 142 7/21/2011 A positive charge might be placed
at one of three spots in a region where
there is a uniform electric field.
How do the electric potential, V, on the
charge at positions 1, 2, and 3 compare?
0% 2. 0% 3. 0% 4. 0% 5. V is greatest at 1
V is greatest at 2
V is greatest at 3
V is 0 at all 3 spots
V is = at all 3 spots
but not = 0.
Physics 142 Summer 2011 A proton is released
from rest at point B,
where the potential is 0
V. Afterward, the
A. moves toward A with a steady speed. B.
0% B. moves toward A with an increasing 0%
C. 0% D.
moves toward C with a steady speed.
moves toward C with an increasing
remains at rest at B.
Physics 142 Summer 2011 Capacitor: Field and Voltage
Parallel plate capacitor: Two identical
conducting plates with equal and opposite
charge density η
E = i 0< x<d ε0 r
E=0 x < 0 and x > d – Field strength inside approx. constant Physics 142 Summer 2011 Dr. Nick Cummings 1 Physics 142 7/21/2011 Two sheets of charge are separated by a distance d ,
small compared to the size of the sheets. The charge
per unit area on the sheets are + η and -η. Select
one graph below that could describe the
Nine Physics 142 Summer 2011 Parallel Plate Capacitor:
Voltage increases in a linear fashion as you
move from the negative plate to the positive Physics 142 Summer 2011 Potential a Point Charge
4πε 0 r Potential for a point charge or
charged sphere Physics 142 Summer 2011 Dr. Nick Cummings 2 Physics 142 7/21/2011 Physics 142 Summer 2011 A
E a) Which set of equipotential
surfaces matches this
b) c) d) e) 0%
c) 0% 0% d) e) Physics 142 Summer 2011 Physics 142 Summer 2011 Dr. Nick Cummings 3 ...
View Full Document