1) A parallel-plate capacitor has plates of area 0.40 m2 and plate separation of 0.20 mm. The

capacitor is connected across a 9.0-V potential source. (ε0 = 8.85 × 10-12 C2/N ∙ m2)

(a) What is the magnitude of the electric field between the plates?

(b) What is the capacitance of the capacitor?

(c) What is the magnitude of the charge on each plate of the capacitor?

5) The capacitance per unit length of a very long coaxial cable, made of two concentric

cylinders, is 50 pF/m. What is the radius of the outer cylinder if the radius of the inner one is 1.0

mm? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

A) 3.0 mm

B) 2.0 mm

C) 4.0 mm

D) 1.0 mm

E) 0.50 mm

11) The capacitors in the network shown in the figure all have a capacitance of 5.0 µF. What is

the equivalent capacitance, Cab, of this capacitor network?

A) 20 µF

B) 3.0 µF

C) 10 µF

D) 5.0 µF

E) 1.0 µF

12) Three capacitors, with capacitances C1 = 4.0 μF, C2 = 3.0 μF, and C3 = 2.0 μF, are

connected to a 12 -V voltage source, as shown in the figure. What is the charge on capacitor C2?

A) 16 μC

B) 32 μC

C) 2.0 μC

D) 8.0 μC

E) 4.0 μC

13) Three capacitors are arranged as shown in the figure. C1 has a capacitance of 5.0 pF, C2 has

a capacitance of 10.0 pF, and C3 has a capacitance of 15.0 pF. Find the voltage drop across the

entire arrangement if the voltage drop across C2 is 311 V. C1 is connected to C2 and C3.

A) 1900 V

B) 1200 V

C) 570 V

D) 520 V

14) The capacitive network shown in the figure is assembled with initially uncharged capacitors.

A potential difference, Vab = +100V, is applied across the network. The switch S in the network

is initially open but is then closed. Assume that all the capacitances shown are accurate to two

significant figures. What is the equivalent capacitance between ab

(a) with the switch S open?

(b) with the switch S closed?

18) A 1.0-μF and a 2.0-μF capacitor are connected in series across a 3.0-V voltage source.

(a) What is the charge on the 1.0-μF capacitor?

(b) What is the voltage across the 2.0-μF capacitor?

Answer: (a) 2.0 µC (b) 1.0 V

19) Three capacitors, of capacitance 5.00 μF, 10.0 μF, and 50.0 μF, are connected in series across

a 12.0-V voltage source.

(a) How much charge is stored in the 5.00-μF capacitor?

(b) What is the potential difference across the 10.0-μF capacitor?

Answer: (a) 37.5 µC (b) 3.75 V

21) Two capacitors of capacitance 6.00 μF and 8.00 μF are connected in parallel. The

combination is then connected in series with a 12.0-V voltage source and a 14.0-μF capacitor, as

shown in the figure.

(a) What is the equivalent capacitance of this combination?

(b) What is the charge on the 6.00-μF capacitor?

(c) What is the potential difference across the 6.00-μF capacitor?

Answer: (a) 7.00 µF (b) 36.0 µC (c) 6.00 V

23) In the circuit shown in the figure, all the capacitors are air-filled. With the switch S open, the

40.0-µF capacitor has an initial charge of 5.00 µC while the other three capacitors are uncharged.

The switch is then closed and left closed for a long time. Calculate the initial and final values of

the total electrical energy stored in these four capacitors.

Answer: Ui = 0.313 µJ, Uf = 0.208 µJ

2) The figure shows three identical lightbulbs connected to a battery having a constant voltage across its

terminals. What happens to the brightness of lightbulb 1 when the switch S is closed?

A) The brightness will increase momentarily then return to its previous level.

B) The brightness increases permanently.

C) The brightness will decrease momentarily then return to its previous level.

D) The brightness remains the same as before the switch is closed.

E) The brightness decreases permanently.

8) A galvanometer G has an internal resistance rg. An AMMETER is constructed by incorporating the

galvanometer and an additional resistance Rs. Which one of the figures below is the most appropriate

circuit diagram for the ammeter?

A) 1

B) 2

C) 3

D) 4

E) 5

1) The power rating of a 400-Ω resistor is 0.800 W.

(a) What is the maximum voltage that can be applied across this resistor without damaging it?

(b) What is the maximum current this resistor can draw without damaging it?

Answer: (a) 17.9 V (b) 44.7 mA

Var: 1

5) A 1500-W heater is connected to a 120-V line. How much heat energy does it produce in 2.0 hours?

A) 1.5 kJ

B) 3.0 kJ

C) 0.18 MJ

D) 11 MJ

E) 18 MJ

11) The emf and the internal resistance of a battery are as shown in the figure. If a current of

8.3 A is drawn from the battery when a resistor R is connected across the terminals ab of the battery, what

is the power dissipated by the resistor R?

A) 440 W

B) 700 W

C) 620 W

D) 530 W

E) 790 W

Answer: A

13) The emf and the internal resistance of a battery are shown in the figure. If a current of 7.8 A is

established through the battery from b to a, what is the terminal voltage Vab of the battery?

A) -30 V

B) 80 V

C) 30 V

D) -80 V

E) zero

17) For the circuit shown in the figure, determine the current in

(a) the 1.0-Ω resistor.

(b) the 3.0-Ω resistor.

(c) the 4.0-Ω resistor.

Answer: (a) 2.8 A (b) 1.2 A (c) 0.90 A

19) Thirteen resistors are connected across points A and B as shown in the figure. If all the resistors are

accurate to 2 significant figures, what is the equivalent resistance between points A and B?

A) 4.0 Ω

B) 6.0 Ω

C) 8.0 Ω

D) 10 Ω

E) 12 Ω

Answer: C

23) Three resistors are connected across an ideal 2.0-V DC battery as shown in the figure.

(a) At what rate does the battery supply energy to the resistors?

(b) At what rate is heat produced in the 6.0-Ω resistor?

Answer: (a) 3.0 W (b) 0.67 W

25) When four identical resistors are connected to an ideal battery of voltage V = 10 V as shown in the

figure, the current I is equal to 0.20 A. What is the value of the resistance R of the resistors?

A) 20 Ω

B) 40 Ω

C) 30 Ω

D) 50 Ω

E) 10 Ω

Answer: C

27) For the circuit shown in the figure, I = 0.50 A and R = 12 Ω. What is the value of the emf ε?

A) 18 V

B) 24 V

C) 6.0 V

D) 12 V

E) 48 V

Answer: B

29) For the circuit shown in the figure, all quantities are accurate to 3 significant figures. What is the

power dissipated in the 2-Ω resistor?

A) 5.33 W

B) 8.0 W

C) 6.67 W

D) 2.67 W

E) 3.56 W

Answer: E

34) For the circuit shown in the figure, what is the current through resistor R1?

A) 0.071 A

B) 0.13 A

C) 0.029 A

D) 0.016 A

Answer: A

37) For the circuit shown in the figure, all quantities are accurate to 2 significant figures. Write 4

equations using Kirchoff’s Junction rule (1 equation) and Loop rule (3 equations). Solving for the value of

the current I subscript 1 is optional in this problem.

A) 0.32 A

B) 0.11 A

C) 0.29 A

D) 0.61 A

E) 0.89 A

Answer: D

38) A multiloop circuit is shown in the figure. It is not necessary to solve the entire circuit. The current I2

is closest to

A) -6 A.

B) 6 A.

C) 8 A.

D) -8 A.

E) zero.

Answer: B

51) A 4.0-mF capacitor is discharged through a 4.0-kΩ resistor. How long will it take for the capacitor to

lose half its initial stored energy?

A) 9.2 s

B) 2.7 s

C) 10.2 s

D) 5.5 s

E) 1.6 s

Answer: D

42) A multiloop circuit is shown in the figure. Some circuit quantities are not labeled. It is not necessary to

solve the entire circuit. The current I2 is closest to

A) +0.1 A.

B) +0.3 A.

C) +0.5 A.

D) -0.1 A.

E) -0.3 A.

Answer: E

54) For the circuit shown in the figure, the switch S is initially open and the capacitor is uncharged. The

switch is then closed at time t = 0. How many seconds after closing the switch will the energy stored in

the capacitor be equal to 50.2 mJ?

A) 81 s

B) 65 s

C) 97 s

D) 110 s

E) 130 s

Answer: A

55) For the circuit shown in the figure, the switch S is initially open and the capacitor voltage is 80 V. The

switch is then closed at time t = 0. What is the charge on the capacitor when the current in the circuit is 33

μA?

A) 1100 µC

B) 1000 µC

C) 960 µC

D) 890 µC

E) 830 µC

Answer: A

7) A charge is accelerated from rest through a potential difference V and then enters a uniform magnetic

field oriented perpendicular to its path. The field deflects the particle into a circular arc of radius R. If the

accelerating potential is tripled to 3V, what will be the radius of the circular arc?

A) 9R

B) 3R

C) R

D) R/

E) R/9

Answer: C

14) A negatively charged particle is moving to the right, directly above a wire having a current flowing to

the right, as shown in the figure. In which direction is the magnetic force exerted on the particle?

A) into the page

B) out of the page

C) downward

D) upward

E) The magnetic force is zero since the velocity is parallel to the current.

Answer: D

19) The figure shows three long, parallel, current-carrying wires. The current directions are indicated for

currents I1 and I3. The arrow labeled F represents the net magnetic force acting on current I3. The three

currents have equal magnitudes. What is the direction of the current I2?

A) into the picture (in the direction opposite to that of I1 and I3)

B) horizontal to the right

C) vertically upward

D) vertically downward

E) out of the picture (in the same direction as I1 and I3)

Answer: A

25) Consider a solenoid of length L, N windings, and radius b (L is much longer than b). A current I is

flowing through the wire. If the length of the solenoid became twice as long (2L), and all other quantities

remained the same, the magnetic field inside the solenoid would

A) remain the same.

B) become twice as strong.

C) become one half as strong.

Answer: C

4) A particle with charge -5.00 C initially moves at = (1.00 + 7.00 ) m/s. If it encounters

a magnetic field find the magnetic force vector on the particle.

A) (-350 + 50.0 ) N

B) (-350 - 50.0 ) N

C) (350 + 50.0 ) N

D) (350 - 50.0 ) N

Answer: A

7) A beam of electrons is accelerated through a potential difference of 10 kV before entering a

region having uniform electric and magnetic fields that are perpendicular to each other and

perpendicular to the direction in which the electron is moving. If the magnetic field in this

region has a value of 0.010 T, what magnitude of the electric field is required if the particles are

to be undeflected as they pass through the region?

A) 2.3 × 103 V/m

B) 7.9 × 103 V/m

C) 5.9 × 105 V/m

D) 6.0 × 105 V/m

E) 7.2 × 106 V/m

Answer: C

10) An alpha particle is moving at a speed of 5.0 × 105 m/s in a direction perpendicular to a

uniform magnetic field of strength 0.040 T. The charge on an alpha particle is 3.2 × 10-19 C and

its mass is 6.6 × 10-27 kg.

(a) What is the radius of the path of the alpha particle?

(b) How long does it take the alpha particle to make one complete revolution around its path?

Answer: (a) 0.26 m (b) 3.2 µs

23) A wire carries a 4.0-A current along the +x-axis through a magnetic field = (5.0 + 7.0 )

T. If the wire experiences a force of 30 N as a result, how long is the wire?

A) 1.1 m

B) 0.87 m

C) 1.5 m

D) 0.63 m

Answer: A

27) A wire segment 1.2 m long carries a current I = 3.5 A, and is oriented as shown in the figure.

The +x-axis points directly into the page. A uniform magnetic field of magnitude 0.50 T pointing

toward the -x direction is present as shown. What is the magnetic force vector on the wire

segment?

A) (+1.1 - 1.8 ) N

B) (-1.1 + 1.8 ) N

C) (-1.1 - 1.8 ) N

D) (+1.8 - 1.1 ) N

E) (-1.8 + 1.1 ) N

Answer: D

30) A rectangular loop of wire carrying a 4.0-A current is placed in a magnetic field of 0.60 T.

The magnitude of the torque acting on this wire when the plane of the loop makes a 30° angle

with the field is measured to be 1.1 N ∙ m. What is the area of this loop?

A) 0.20 m2

B) 0.40 m2

C) 0.26 m2

D) 0.80 m2

E) 0.53 m2

Answer: E

31) A circular loop of diameter 10 cm, carrying a current of 0.20 A, is placed inside a magnetic

field = 0.30 T . The normal to the loop is parallel to a unit vector = -0.60 - 0.80 .

Calculate the magnitude of the torque on the loop due to the magnetic field.

A) 4.7 × 10-4 N ∙ m

B) 2.8 × 10-4 N ∙ m

C) 0.60 × 10-4 N ∙ m

D) 1.2 × 10-4 N ∙ m

E) zero

Answer: A

33) A rigid circular loop has a radius of 0.20 m and is in the xy-plane. A clockwise current I is

carried by the loop, as shown. The magnitude of the magnetic moment of the loop is 0.75 A ·

m2. A uniform external magnetic field, B = 0.20 T in the positive x-direction, is present.

(a) What is the current in the loop?

(b) Find the magnitude of the magnetic torque exerted on the loop.

(c) If the loop is released from rest, in what direction will points a and c initially move?

Answer:

(a) 6.0 A (b) 0.15 N ∙ m

(c) a moves out of the plane and c moves into the plane

34) A circular coil of wire of 200 turns and diameter 2.0 cm carries a current of 4.0 A. It is

placed in a magnetic field of 0.70 T with the plane of the coil making an angle of 30° with the

magnetic field. What is the magnetic torque on the coil?

A) 0.15 N ∙ m

B) 0.088 N ∙ m

C) 0.29 N ∙ m

D) 0.40 N ∙ m

E) 0.076 N ∙ m

Answer: A