Potential4.5
Which path requires the most work on charge
+q by an external agent?
E field
(i)
A
+q
B
(f)
C
D: All are the same
©University of Colorado, Boulder
(2008)
Potential5
A positive charge q is moved from position i to
position f between the plates of a charged
capacitor.
E
Did the pot. energy (U)
increase or decrease?
Did the voltage (V) at the
position of the test charge
increase or decrease?
f
A: U ,
V
B: U , V
C: U ,
V
D: U , V
E: None of these
i
+q
Potential 6
A negative charge -q is moved from position i to
position f between the plates of a charged capacitor.
Did the pot. energy (U)
increase or decrease?
Did the voltage (V) at the
position of the test charge
increase or decrease?
E
f
A: U ,
V
B: U , V
C: U ,
V
D: U , V
E: None of these
i
-q
Potential 7
A small positive test charge is initially at rest in an
electric field, and is free to move.
Which way will the charge start to move?
A: Moves towards higher potential (V).
B: Moves towards lower potential.
C: Not enough information given.
©University of Colorado, Boulder
(2008)
Potential 8
A small negative test charge is initially at rest in
an electric field, and is free to move.
Which way will the charge start to move?
A: Moves towards higher potential (V).
B: Moves towards lower potential.
C: Not enough information given.
©University of Colorado, Boulder
(2008)
Potential 9
Two test charges are brought separately into the
vicinity of a fixed charge +Q.
i: +q is brought to point A, "r" away.
ii: -q is brought to the same point.
(U=0 and V=0 at ∞)
The potential, V, at
point P is ...
i:
+q
+Q
P
r
+Q
ii:
A: Greater for the +q
r
charge in situation i
B: Greater for the -q charge in situation ii
C: The same for both.
-q
P
Potential 10
The potential energy, U of the test
charge is greater in situation...
A: i
i:
+q
+Q
B : ii
C: The same for both. ii:
P
r
+Q
-q
r
P