Question 1

In the circuit shown in the figure, R1 = 10 Ω, R2 = 12 Ω, R3 = 20 Ω, V1 = 1.0 V, V2 = 7.0 V, and the batteries are both ideal. What is the current through R1?

Accepted Answer

A)  0.60 A 
B)  0.80 A 
C)  0.18 A 
D)  0.13 A 
A)  0.60 A 
B)  0.80 A 
C)  0.18 A 
D)  0.13 A

Question 2

A 2.0-Ω resistor is in series with a parallel combination of 4.0-Ω, 6.0-Ω, and 12-Ω resistors. What is the equivalent resistance of this system?

Accepted Answer

A)  24 Ω 
B)  4.0 Ω 
C)  1.8 Ω 
D)  2.7 Ω 
A)  24 Ω 
B)  4.0 Ω 
C)  1.8 Ω 
D)  2.7 Ω

Question 3

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source. What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

Accepted Answer

A)  The brightness of the lamps will not change appreciably. 
B)  The other lamps get brighter equally. 
C)  The other lamps get brighter, but some get brighter than others. 
D)  The other lamps get dimmer equally. 
E)  The other lamps get dimmer, but some get dimmer than others. 
A)  The brightness of the lamps will not change appreciably. 
B)  The other lamps get brighter equally. 
C)  The other lamps get brighter, but some get brighter than others. 
D)  The other lamps get dimmer equally. 
E)  The other lamps get dimmer, but some get dimmer than others.

Question 4

A resistor, an uncharged capacitor, a dc voltage source, and an open switch are all connected in series. The switch is closed at time t = 0 s. Which one of the following is a correct statement about this circuit?

Accepted Answer

A)  The charge on the capacitor after four time constants is about 98% of the maximum value. 
B)  The charge on the capacitor after one time constant is 50% of its maximum value. 
C)  The charge on the capacitor after one time constant is 1/e of its maximum value. 
D)  The voltage on the capacitor after one time constant is 1/e of the maximum value. 
E)  The voltage on this capacitor after one time constant is 100% of its maximum value. 
A)  The charge on the capacitor after four time constants is about 98% of the maximum value. 
B)  The charge on the capacitor after one time constant is 50% of its maximum value. 
C)  The charge on the capacitor after one time constant is 1/e of its maximum value. 
D)  The voltage on the capacitor after one time constant is 1/e of the maximum value. 
E)  The voltage on this capacitor after one time constant is 100% of its maximum value.

Question 5

Draw a circuit with a battery connected to four resistors, R1, R2, R3, and R4, as follows. Resistors R1 and R2 are connected in parallel with each other, resistors R3 and R4 are connected in parallel with each other, and both parallel sets of resistors are connected in series with each other across the battery.

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 6

When an initially uncharged capacitor is charged through a 25-kΩ resistor by a 75-V dc ideal power source, it takes 0.23 ms for the capacitor to reach 50% of its maximum charge? What is the capacitance of this capacitor?

Accepted Answer

The answer of When an initially uncharged capacitor is charged...

Question 7

A series circuit consists of a 2.5-μF capacitor, a 7.6-MΩ resistor, and an ideal 6.0-V dc power source.
(a) What is the time constant for charging the capacitor?
(b) What is the potential difference across the capacitor 25 s after charging begins?

Accepted Answer

The answer of A series circuit consists of a 2.5-μF...

Question 8

Four resistors are connected across an ideal dc battery with voltage V, as shown in the figure. If the total current in this circuit is I = 1 A, what is the value of the voltage V?

Accepted Answer

A)  2 V 
B)  4 V 
C)  6 V 
D)  8 V 
E)  10 V 
A)  2 V 
B)  4 V 
C)  6 V 
D)  8 V 
E)  10 V

Question 9

A 1.0-μF capacitor is charged until it acquires a potential difference of $900.0 \mathrm {~V}$ across its plates, and then the emf source is removed. If the capacitor is then discharged through a $500.0 - \mathrm { k } \Omega$ resistance, what is the voltage drop across the capacitor $9.0 \mathrm {~ms}$ after beginning the discharge?

Accepted Answer

A)  880 V 
B)  920 V 
C)  16 V 
D)  -16 V 
A)  880 V 
B)  920 V 
C)  16 V 
D)  -16 V

Question 10

A number of resistors are connected across points A and B as shown in the figure. What is the equivalent resistance between points A and B?

Accepted Answer

A)  4 Ω 
B)  6 Ω 
C)  8 Ω 
D)  10 Ω 
E)  12 Ω 
A)  4 Ω 
B)  6 Ω 
C)  8 Ω 
D)  10 Ω 
E)  12 Ω

Question 11

A 4.0-Ω resistor is connected with a 12-Ω resistor and this combination is connected across an ideal dc power supply with V = 6.0 V, as shown in the figure. When a total current I flows from the power supply, what is the current through the 12-Ω resistor?

Accepted Answer

A)  1.5 A 
B)  2.0 A 
C)  2.5 A 
D)  3.0 A 
E)  0.50 A 
A)  1.5 A 
B)  2.0 A 
C)  2.5 A 
D)  3.0 A 
E)  0.50 A

Question 12

A 9-V battery is hooked up to two resistors in series using wires of negligible resistance. One has a resistance of 5 Ω, and the other has a resistance of 10 Ω. Several locations along the circuit are marked with letters, as shown in the figure. Which statements about this circuit are true? (There could be more than one correct choice.)

Accepted Answer

A)  The current is exactly the same at points A, B, C, and D. 
B)  The current at A is greater than the current at B, which is equal to the current at C, which is greater than the current at D. 
C)  The current at A is greater than the current at B, which is greater than the current at C, which is greater than the current at D. 
D)  The potential at B is equal to the potential at C. 
E)  The potential at D is equal to the potential at C. 
A)  The current is exactly the same at points A, B, C, and D. 
B)  The current at A is greater than the current at B, which is equal to the current at C, which is greater than the current at D. 
C)  The current at A is greater than the current at B, which is greater than the current at C, which is greater than the current at D. 
D)  The potential at B is equal to the potential at C. 
E)  The potential at D is equal to the potential at C.

Question 13

In the circuit shown in the figure, R1 = 60 Ω, R2 = 120 Ω, R3 = 180 Ω, V1 = 3.0 V, V2 = 6.0 V, and the batteries are both ideal. What is the current through R1?

Accepted Answer

A)  0.050 A 
B)  0.030 A 
C)  0.00 A 
D)  2.68 A 
A)  0.050 A 
B)  0.030 A 
C)  0.00 A 
D)  2.68 A

Question 14

Three 2.0-Ω resistors are connected to form the sides of an equilateral triangle ABC as shown in the figure. What is the equivalent resistance between any two points, AB, BC, or AC, of this circuit?

Accepted Answer

A)  2.0 Ω 
B)  6.0 Ω 
C)  4.3 Ω 
D)  3.3 Ω 
E)  1.3 Ω 
A)  2.0 Ω 
B)  6.0 Ω 
C)  4.3 Ω 
D)  3.3 Ω 
E)  1.3 Ω

Question 15

A capacitor C is connected in series with a resistor R across a battery and an open switch. If a second capacitor of capacitance 2C is connected in series with the first one, the time constant of the new RC circuit will be

Accepted Answer

A)  the same as before. 
B)  larger than before. 
C)  smaller than before. 
D)  variable. 
A)  the same as before. 
B)  larger than before. 
C)  smaller than before. 
D)  variable.

Question 16

What is the potential drop from point A to point B for the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Accepted Answer

A)  0.35 V 
B)  2.0 V 
C)  2.5 V 
D)  3.0 V 
A)  0.35 V 
B)  2.0 V 
C)  2.5 V 
D)  3.0 V

Question 17

Three capacitors of capacitance 5.00 μF, 10.0 μF, and 50.0 μF are connected in series across a 12.0-V potential difference (a battery).
(a) How much charge is stored in the 5.00-μF capacitor?
(b) What is the potential difference across the 10.0-µF capacitor?

Accepted Answer

(a) 37.5 µ

Question 18

Three identical capacitors are connected in series across a potential source (battery). If a charge of Q flows into this combination of capacitors, how much charge does each capacitor carry?

Accepted Answer

A)  3Q 
B)  Q 
C)  Q/3 
D)  Q/9 
A)  3Q 
B)  Q 
C)  Q/3 
D)  Q/9

Question 19

A 5.0-μF, a 14-μF, and a $21 - \mu \mathrm { F }$ capacitor are connected in parallel. How much capacitance would a single capacitor need to have to replace the three capacitors?

Accepted Answer

A)  40 μF 
B)  21  μF 
C)  5.0 μF 
D)  14 μF 
A)  40 μF 
B)  21  μF 
C)  5.0 μF 
D)  14 μF

Question 20

A charged capacitor is connected in series with a resistor and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the charge Q on the capacitor as a function of time t?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Exam 23: Circuits

In the circuit shown in the figure, R1 = 10 Ω, R2 = 12 Ω, R3 = 20 Ω, V1 = 1.0 V, V2 = 7.0 V, and the batteries are both ideal. What is the current through R1?

A 2.0-Ω resistor is in series with a parallel combination of 4.0-Ω, 6.0-Ω, and 12-Ω resistors. What is the equivalent resistance of this system?

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source. What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

A resistor, an uncharged capacitor, a dc voltage source, and an open switch are all connected in series. The switch is closed at time t = 0 s. Which one of the following is a correct statement about this circuit?

When an initially uncharged capacitor is charged through a 25-kΩ resistor by a 75-V dc ideal power source, it takes 0.23 ms for the capacitor to reach 50% of its maximum charge? What is the capacitance of this capacitor?

A series circuit consists of a 2.5-μF capacitor, a 7.6-MΩ resistor, and an ideal 6.0-V dc power source. (a) What is the time constant for charging the capacitor? (b) What is the potential difference across the capacitor 25 s after charging begins?

Four resistors are connected across an ideal dc battery with voltage V, as shown in the figure. If the total current in this circuit is I = 1 A, what is the value of the voltage V?

A number of resistors are connected across points A and B as shown in the figure. What is the equivalent resistance between points A and B?

A 4.0-Ω resistor is connected with a 12-Ω resistor and this combination is connected across an ideal dc power supply with V = 6.0 V, as shown in the figure. When a total current I flows from the power supply, what is the current through the 12-Ω resistor?

In the circuit shown in the figure, R1 = 60 Ω, R2 = 120 Ω, R3 = 180 Ω, V1 = 3.0 V, V2 = 6.0 V, and the batteries are both ideal. What is the current through R1?

Three 2.0-Ω resistors are connected to form the sides of an equilateral triangle ABC as shown in the figure. What is the equivalent resistance between any two points, AB, BC, or AC, of this circuit?

A capacitor C is connected in series with a resistor R across a battery and an open switch. If a second capacitor of capacitance 2C is connected in series with the first one, the time constant of the new RC circuit will be

What is the potential drop from point A to point B for the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Three capacitors of capacitance 5.00 μF, 10.0 μF, and 50.0 μF are connected in series across a 12.0-V potential difference (a battery). (a) How much charge is stored in the 5.00-μF capacitor? (b) What is the potential difference across the 10.0-µF capacitor?

Three identical capacitors are connected in series across a potential source (battery). If a charge of Q flows into this combination of capacitors, how much charge does each capacitor carry?

A 5.0-μF, a 14-μF, and a 21−μF21 - \mu \mathrm { F }21−μF capacitor are connected in parallel. How much capacitance would a single capacitor need to have to replace the three capacitors?

A charged capacitor is connected in series with a resistor and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the charge Q on the capacitor as a function of time t?

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Forces and Newtons Laws of Motion

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Filters

In the circuit shown in the figure, R₁ = 10 Ω, R₂ = 12 Ω, R₃ = 20 Ω, V₁ = 1.0 V, V₂ = 7.0 V, and the batteries are both ideal. What is the current through R₁?

In the circuit shown in the figure, R₁ = 60 Ω, R₂ = 120 Ω, R₃ = 180 Ω, V₁ = 3.0 V, V₂ = 6.0 V, and the batteries are both ideal. What is the current through R₁?

A 5.0-μF, a 14-μF, and a $21 - \mu \mathrm { F }$ capacitor are connected in parallel. How much capacitance would a single capacitor need to have to replace the three capacitors?