Question 1

Four resistors having resistances of 20 Ω, 40 Ω, 60 Ω, and 80 Ω are connected in series across an ideal 50-V dc source. What is the current through each resistor?

Accepted Answer

A)  0.25 A 
B)  0.50 A 
C)  0.75 A 
D)  2.0 A 
E)  4.0 A 
A)  0.25 A 
B)  0.50 A 
C)  0.75 A 
D)  2.0 A 
E)  4.0 A

Question 2

Determine the current in the 7.0-Ω resistor for the circuit shown in the figure. Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

Accepted Answer

A)  0.28 A 
B)  1.3 A 
C)  1.6 A 
D)  2.1 A 
A)  0.28 A 
B)  1.3 A 
C)  1.6 A 
D)  2.1 A

Question 3

When unequal resistors are connected in parallel in a circuit,

Accepted Answer

A)  the same current always runs through each resistor. 
B)  the potential drop is always the same across each resistor. 
C)  the largest resistance has the largest current through it. 
D)  the power generated in each resistor is the same. 
A)  the same current always runs through each resistor. 
B)  the potential drop is always the same across each resistor. 
C)  the largest resistance has the largest current through it. 
D)  the power generated in each resistor is the same.

Question 4

A15-Ω resistor is connected in parallel with a 30-Ω resistor. If this combination is now connected in series with an ideal 9.0-V battery and a 20-Ω resistor, what is the current through the 15-Ω resistor?

Accepted Answer

A)  0.10 A 
B)  0.13 A 
C)  0.20 A 
D)  0.26 A 
A)  0.10 A 
B)  0.13 A 
C)  0.20 A 
D)  0.26 A

Question 5

A 5-µF, a 7-µF, and an unknown capacitor CX are connected in parallel between points a and b as shown in the figure. What do you know about the equivalent capacitance Cab between a and b? (There could be more than one correct choice.)

Accepted Answer

A)  Cab > 12 µF 
B)  Cab > CX 
C)  5 µF ab ab ab X 
A)  Cab > 12 µF 
B)  Cab > CX 
C)  5 µF ab ab ab X

Question 6

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 potential difference V across the resistor as a function of time t?

Accepted Answer

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

Question 7

Identical ideal batteries are connected in different arrangements to the same light bulb, as shown in the figure. For which arrangement will the bulb shine the brightest? 
(A)
 
(B)
 
(C)

Accepted Answer

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

Question 8

Each of the resistors shown in the figure has a resistance of $180.0 \Omega$
 What is the equivalent resistance between points a and b of this combination?

Accepted Answer

A)  450.0 Ω 
B)  720.0 Ω 
C)  540.0 Ω 
D)  180.0 Ω 
A)  450.0 Ω 
B)  720.0 Ω 
C)  540.0 Ω 
D)  180.0 Ω

Question 9

A 3.0-Ω resistor is connected in parallel with a 6.0-Ω resistor. This combination is then connected in series with a 4.0-Ω resistor. The resistors are connected across an ideal 12-volt battery. How much power is dissipated in the 3.0-Ω resistor?

Accepted Answer

A)  2.7 W 
B)  5.3 W 
C)  6.0 W 
D)  12 W 
A)  2.7 W 
B)  5.3 W 
C)  6.0 W 
D)  12 W

Question 10

Four unequal resistors are connected in a parallel with each other. Which one of the following statements is correct about this combination?

Accepted Answer

A)  The equivalent resistance is less than that of the smallest resistor. 
B)  The equivalent resistance is equal to the average of the four resistances. 
C)  The equivalent resistance is midway between the largest and smallest resistance. 
D)  The equivalent resistance is more than the largest resistance. 
E)  None of the other choices is correct. 
A)  The equivalent resistance is less than that of the smallest resistor. 
B)  The equivalent resistance is equal to the average of the four resistances. 
C)  The equivalent resistance is midway between the largest and smallest resistance. 
D)  The equivalent resistance is more than the largest resistance. 
E)  None of the other choices is correct.

Question 11

A 2.0-μF capacitor that is initially uncharged is charged through a 50-kΩ resistor. How long does it take for the capacitor to reach 90% of its full charge?

Accepted Answer

A)  0.90 s 
B)  0.23 s 
C)  2.2 s 
D)  2.3 s 
A)  0.90 s 
B)  0.23 s 
C)  2.2 s 
D)  2.3 s

Question 12

Draw a circuit with two batteries, a resistor between them, and a capacitor in parallel with the resistor. The batteries are connected negative pole to positive pole.

Accepted Answer

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

Question 13

The network shown is assembled with uncharged capacitors X , Y, and Z, with $C X = 4.0 \mu \mathrm { F }$ $\mathrm { CY } = 3.0 \mu \mathrm { F }$ and $C Z = 5.0 \mu \mathrm { F }$ The switches S1 and S2 are initially open, and a potential difference Vab = 120 V is applied between points a and b. After the network is assembled, switch S1 is then closed, but switch S2 is kept open. How much energy is finally stored in capacitor X?

Accepted Answer

A)  29 mJ 
B)  0.48 mJ 
C)  0.24 mJ 
D)  58 mJ 
E)  0.96 mJ 
A)  29 mJ 
B)  0.48 mJ 
C)  0.24 mJ 
D)  58 mJ 
E)  0.96 mJ

Question 14

For the circuit shown in the figure, V = 60 V, C = 40 µF, R = 0.90 MΩ, and the battery is ideal. Initially the switch S is open and the capacitor is uncharged. The switch is then closed at time t = 0.00 s. At a given instant after closing the switch, the potential difference across the capacitor is twice the potential difference across the resistor. At that instant, what is the charge on the capacitor?

Accepted Answer

A)  1600 µC 
B)  1400 µC 
C)  1200 µC 
D)  890 µC 
E)  600 µC 
A)  1600 µC 
B)  1400 µC 
C)  1200 µC 
D)  890 µC 
E)  600 µC

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 parallel with the first one, the time constant of the new RC circuit will be

Accepted Answer

A)  the same as before. 
B)  twice as large as before. 
C)  three times a large as before. 
D)  one-half as large as before. 
E)  one-fourth as large as before. 
A)  the same as before. 
B)  twice as large as before. 
C)  three times a large as before. 
D)  one-half as large as before. 
E)  one-fourth as large as before.

Question 16

For the circuit shown in the figure, V = 60 V, C = 20 µF, R = 0.10 MΩ, and the battery is ideal. Initially the switch S is open and the capacitor is uncharged. The switch is then closed at time t = 0.00 s. What is the charge on the capacitor 8.0 s after closing the switch?

Accepted Answer

A)  1200 µC 
B)  940 µC 
C)  1400 µC 
D)  1600 µC 
E)  1900 µC 
A)  1200 µC 
B)  940 µC 
C)  1400 µC 
D)  1600 µC 
E)  1900 µC

Question 17

A 5.0-μF capacitor and a 7.0-μF capacitor are connected in series across an 8.0-V potential source. What is the potential difference across the 5.0-μF capacitor?

Accepted Answer

A)  0 V 
B)  8.0 V 
C)  2.7 V 
D)  3.6 V 
E)  4.7 V 
A)  0 V 
B)  8.0 V 
C)  2.7 V 
D)  3.6 V 
E)  4.7 V

Question 18

Identical light bulbs can be attached to identical ideal batteries in three different ways (A, B, orC), as shown in the figure. The ranking (from lowest to highest) of the total power produced by the battery is

Accepted Answer

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

Question 19

A 5.0-μF, a 14-μF, and a 21-μF capacitor are connected in series. How much capacitance would a single capacitor need to have to replace the three capacitors?

Accepted Answer

A)  40 μF 
B)  3.6 μF 
C)  2.0 μF 
D)  3.1 μF 
A)  40 μF 
B)  3.6 μF 
C)  2.0 μF 
D)  3.1 μF

Question 20

What is the magnitude of the potential difference between points C and D for the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Accepted Answer

A)  6.0 V 
B)  4.0 V 
C)  3.0 V 
D)  2.0 V 
A)  6.0 V 
B)  4.0 V 
C)  3.0 V 
D)  2.0 V

Exam 23: Circuits

Four resistors having resistances of 20 Ω, 40 Ω, 60 Ω, and 80 Ω are connected in series across an ideal 50-V dc source. What is the current through each resistor?

Determine the current in the 7.0-Ω resistor for the circuit shown in the figure. Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

When unequal resistors are connected in parallel in a circuit,

A15-Ω resistor is connected in parallel with a 30-Ω resistor. If this combination is now connected in series with an ideal 9.0-V battery and a 20-Ω resistor, what is the current through the 15-Ω resistor?

A 5-µF, a 7-µF, and an unknown capacitor CX are connected in parallel between points a and b as shown in the figure. What do you know about the equivalent capacitance Cab between a and b? (There could be more than one correct choice.)

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 potential difference V across the resistor as a function of time t?

Identical ideal batteries are connected in different arrangements to the same light bulb, as shown in the figure. For which arrangement will the bulb shine the brightest? (A) (B) (C)

Each of the resistors shown in the figure has a resistance of 180.0Ω180.0 \Omega180.0Ω What is the equivalent resistance between points a and b of this combination?

A 3.0-Ω resistor is connected in parallel with a 6.0-Ω resistor. This combination is then connected in series with a 4.0-Ω resistor. The resistors are connected across an ideal 12-volt battery. How much power is dissipated in the 3.0-Ω resistor?

Four unequal resistors are connected in a parallel with each other. Which one of the following statements is correct about this combination?

A 2.0-μF capacitor that is initially uncharged is charged through a 50-kΩ resistor. How long does it take for the capacitor to reach 90% of its full charge?

Draw a circuit with two batteries, a resistor between them, and a capacitor in parallel with the resistor. The batteries are connected negative pole to positive pole.

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 parallel with the first one, the time constant of the new RC circuit will be

For the circuit shown in the figure, V = 60 V, C = 20 µF, R = 0.10 MΩ, and the battery is ideal. Initially the switch S is open and the capacitor is uncharged. The switch is then closed at time t = 0.00 s. What is the charge on the capacitor 8.0 s after closing the switch?

A 5.0-μF capacitor and a 7.0-μF capacitor are connected in series across an 8.0-V potential source. What is the potential difference across the 5.0-μF capacitor?

Identical light bulbs can be attached to identical ideal batteries in three different ways (A, B, orC), as shown in the figure. The ranking (from lowest to highest) of the total power produced by the battery is

A 5.0-μF, a 14-μF, and a 21-μF capacitor are connected in series. How much capacitance would a single capacitor need to have to replace the three capacitors?

What is the magnitude of the potential difference between points C and D for the circuit shown in the figure? The battery is ideal, and all the numbers are accurate to two significant figures.

Representing Motion

Motion in One Dimension

Vectors and Motion in Two Dimensions

Forces and Newtons Laws of Motion

Applying Newtons Laws

Gravity

Rotational Motion

Equilibrium Ad Elasticity

Momentum

Energy and Work

Using Energy

Thermal Properties of Matter

Fluids

Oscillations

Traveling Waves and Sound

Superposition and Standing Waves

Wave Optics

Ray Optics

Optical Instruments

Electric Fields and Forces

Electric Potential

Current and Resistance

Magnetic Fields and Forces

EM Induction and Em Waves

AC Electricity

Relativity

Quantum Physics

Atoms and Molecules

Nuclear Physics

Filters

A 5-µF, a 7-µF, and an unknown capacitor C_X are connected in parallel between points a and b as shown in the figure. What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice.)