Chapter 17      Sample Multiple Choice Problems

1.       A proton, initially at rest, is accelerated through an electric potential difference of 500 V.  What is the kinetic energy of the proton?

a.   500 J

b.   8.0X10-17 J

c.   1.6X10-19 J

d.   zero

2.       It takes 10 J of energy to move 2.0 C of charge from point A to point B.  What is the potential difference between points A and B?

a.   20 V

b.   0.20 V

c.   5.0 V

d.   0.50 V

3.       A 12-V battery maintains the electrical potential difference between two parallel metal plates separated by 10 cm.  What is the electric field between the plates?

a.   1.2 V/m

b.   12 V/m

c.   120 V/m

d.   zero

4.       The electron-volt is a unit of

a.   voltage.

b.   current.

c.   power.

d.   energy.

5.       Two parallel plates, separated by 0.20 m, are connected to a 12-V battery.  An electron released from rest at a location 0.10 m from the negative plate.  When the electron arrives at a distance 0.050 m from the positive plate, what is the potential difference between the initial and final points?

a.   2.4 V

b.   3.0 V

c.   4.8 V

d.   6.0 V

6.       A uniform electric field, with a magnitude of 500 V/m, is directed parallel to the +x axis.  If the potential at x = 5.0 m is 2500 V, what is the potential at x = 2.0 m?

a.   500 V

b.   1000 V

c.   2000 V

d.   4000 V

7.       Two 3.00-μC charges are at the ends of a meterstick.  Find the electrical potential for the center of

the meterstick.

a.   zero

b.   2.70X104 V

c.   5.40X104 V

d.   1.08X105 V

8.       What charge appears on the plates of a 2.0 μF capacitor when it is charged to 100 V?

a.   50   μC

b.   100 μC

c.   150 μC

d.   200 μC

9.       A parallel plate capacitor is constructed with plate area of 0.40 m2 and a plate separation of 0.10 mm.  How much charge is stored on it when it is charged to a potential difference of 12 V?

a.   0.21 μC

b.   0.42 μC

c.   0.63 μC

d.   0.84 μC

10.     A charge of 60 μC is placed on a 15 μF capacitor.  How much energy is stored in the capacitor?

a.   120 J

b.   4.0 J

c.   240 μJ

d.   120 μJ

11.     A parallel-plate capacitor has plates of area 0.20 m2 separated by a distance of 1.0 mm.  What is this capacitor's capacitance?

a.   200 F

b.   40 F

c.   1.8X10-9 F

d.   3.5X10-10 F

12.     Doubling the voltage across a given capacitor causes the energy stored in that capacitor to

b.   double.

c.   reduce to one half.

d.   reduce to one fourth.

13.     If the electric field between the plates of a given capacitor is weakened, the capacitance of that capacitor

a.   increases.

b.   decreases.

c.   does not change.

d.   cannot be determined from the information given.

14.     Two parallel-plate capacitors are identical in every respect except that one has twice the plate area of

the other.  If the smaller capacitor has capacitance C, the larger one has capacitance

a.   C/2

b.   C

c.   2C

d.   4C

15.     A charge of 2.00 μC flows onto the plates of a capacitor when it is connected to a 12.0-V battery.  How much work was done in charging this capacitor?

a.   24.0 μJ

b.   12.0 μJ

c.   144 μJ

d.   576 J

1.       b

2.       c

3.       c

4.       d

5.       b

6.       d

7.       d

8.       d

9.       b

10.     d

11.     c

12.     a

13.     c

14.     c

15.     b