Transcript multiple-choice questions II (for homework on 1/29)

10. Equipotential Surfaces III
Which of these configurations gives V = 0 at all points on the y-axis?
+2mC
+1mC
+2mC
+1mC
x
-1mC
-2mC
+2mC
-2mC
x
-2mC
-1mC
1)
x
2)
4) all of the above
+1mC
-1mC
3)
5) none of the above
11. Equipotential of Point Charge
1) A and C
Which two points have
the same potential?
2) B and E
3) B and D
4) C and E
5) no pair
A
C
B
E
Q
D
12. Work and Electric Potential I
1) P  1
Which requires the most work,
to move a positive charge from
P to points 1, 2, 3 or 4 ? All
points are the same distance
from P.
2) P  2
3) P  3
4) P  4
5) all require the same
amount of work
3
2
1
P

E
4
13. Work and Electric Potential II
1) P  1
Which requires zero work, to
move a positive charge from
P to points 1, 2, 3 or 4 ? All
points are the same distance
from P.
2) P  2
3) P  3
4) P  4
5) all require the same
amount of work
3
2
1
P

E
4
14. Capacitors
Capacitor C1 is connected across
1) C1
a battery of 5 V. An identical
2) C2
capacitor C2 is connected across
a battery of 10 V. Which one has
3) both have the same charge
4) it depends on other factors
the most charge?
+Q –Q
15. Varying Capacitance I
What must be done to
1) increase the area of the plates
a capacitor in order to
2) decrease separation between the plates
increase the amount of
3) decrease the area of the plates
charge it can hold (for
a constant voltage)?
4) either (1) or (2)
5) either (2) or (3)
+Q –Q
16. Varying Capacitance II
A parallel-plate capacitor
1) the voltage decreases
initially has a voltage of 400 V
2) the voltage increases
and stays connected to the
3) the charge decreases
battery. If the plate spacing is
now doubled, what happens?
4) the charge increases
5) both voltage and charge change
+Q –Q
17. Varying Capacitance III
A parallel-plate capacitor initially has
a potential difference of 400 V and is
then disconnected from the charging
battery. If the plate spacing is now
doubled (without changing Q), what
is the new value of the voltage?
+Q –Q
1) 100 V
2) 200 V
3) 400 V
4) 800 V
5) 1600 V