Physics II 1420 Ch 20

What is the equivalent capacitance of the combination of capacitors shown in the circuit?

0.67 µF

Determine the power dissipated by the 40-Ω resistor in the circuit shown.

3.6 W

Three resistors, 50-Ω, 120-Ω, 180-Ω, are connected in series in a circuit. What is the equivalent resistance of this combination of resistors?

350 Ω

The figure shows a simple RC circuit consisting of a 10.0-µF capacitor in series with a resistor. Initially, the switch is open as suggested in the figure. The capacitor has been charged so that the potential difference between its plates is 100.0 V. At t = 0 s, the switch is closed. The capacitor discharges exponentially so that 2.0 s after the switch is closed, the potential difference between the capacitor plates is 37 V. In other words, in 2.0 s the potential difference between the capacitor plates is reduced to 37 % of its original value. Determine the potential drop across the resistor R at t = 2.0 s (i.e., two seconds after the switch is closed).

37 V

When a light bulb is connected to a 4.5 V battery, a current of 0.12 A passes through the bulb filament. What is the resistance of the filament?

38 Ω

Three resistors are connected as shown in the figure. The potential difference between points A and B is 26 V. What is the equivalent resistance between the points A and B?

4.3 Ω

Which one of the following quantities can be converted to kilowatt ⋅ hours (kWh)?

5.8 J

Two wires, A and B, and a variable resistor, R, are connected in series to a battery. Which one of the following results will occur if the resistance of R is increased?

The current through the entire circuit will decrease

The current through a certain heater wire is found to be fairly independent of its temperature. If the current through the heater wire is doubled, the amount of energy delivered by the heater in a given time interval will

increase by a factor of four.

Four resistors and a 6-V battery are arranged as shown in the circuit diagram. The largest potential difference is across which resistor(s)?

the 20-Ω resistor

Complete the following statement: The electromotive force is

the maximum potential difference between the terminals of a battery.

The gauge is a measure of the diameter of the wire; and #18 corresponds to a diameter of 1.2 × 10⁻³ m; and #22 corresponds to a diameter of 6.4 × 10⁻⁴ m. The resistivity of iron is 9.7 × 10⁻⁸ Ω ⋅ m; and the value for copper is 1.72 × 10⁻⁸ Ω ⋅ m. Which one of the wires carries the smallest current when they are connected to identical batteries?

wire A

The gauge is a measure of the diameter of the wire; and #18 corresponds to a diameter of 1.2 × 10⁻³ m; and #22 corresponds to a diameter of 6.4 × 10⁻⁴ m. The resistivity of iron is 9.7 × 10⁻⁸ Ω ⋅ m; and the value for copper is 1.72 × 10⁻⁸ Ω ⋅ m. Of the five wires, which one has the smallest resistance?

wire D

An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C₁ and C₂, with capacitances of 20.0 µF and 60.0 µF, respectively. Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. What is the current through the resistor a long time after the switch is closed? Recall that current is the charge per unit time that flows in a circuit.

zero amperes

The figure shows a circuit. The switch S can be closed on either point A or C, but not both at the same time. Use the following quantities: V1 = V2 = 12 V R1 = R4 = 1.0 Ω R2 = R3 = 2.0 Ω Determine the current through R4 when the switch S is closed on C.

zero amperes

Which one of the following circuits has the largest resistance?

E

Which one of the following combinations of units is equivalent to the ohm?

J⋅s/C²

Three resistors and two 10.0-V batteries are arranged as shown in the circuit diagram. Which one of the following entries in the table is correct?

Power Delivered by Battery 1 1.0 W Power Delivered by Battery 2 4.0 W

A battery has a terminal voltage of 12 V when no current flows and an internal resistance of 2 Ω. The battery is placed in series with a 1-Ω resistor. Which one of the entries in the following table is correct?

Terminal voltage 4 V Current through the 1-Ω resistor 4 A

The potential difference across the ends of a wire is doubled in magnitude. If Ohm's law is obeyed, which one of the following statements concerning the resistance of the wire is true?

The resistance is not changed.

Which one of the following statements concerning resistance is true?

The resistance of a metal wire changes with temperature.

Which one of the following statements concerning capacitors of unequal capacitance connected in series is true?

The total voltage supplied by the battery is the sum of the voltages across each capacitor.

A physics student performed an experiment in which the potential difference V between the ends of a long straight wire was varied. The current I in the wire was measured at each value of the potential difference with an ammeter and the results of the experiment are shown in the table. Which one of the following statements is the best conclusion based on the data?

The wire obeys Ohm's law over the range of potential differences between 5 and 20 V.

Which one of the following situations results in a conventional electric current that flows northward?

a beam of electrons moves southward

Complete the following statement: The unit kilowatt ⋅ hour measures

energy.

Complete the following statement: A simple series circuit contains a resistance R and an ideal battery. If a second resistor is connected in parallel with R,

the total current through the battery will increase.

The gauge is a measure of the diameter of the wire; and #18 corresponds to a diameter of 1.2 × 10⁻³ m; and #22 corresponds to a diameter of 6.4 × 10⁻⁴ m. The resistivity of iron is 9.7 × 10⁻⁸ Ω ⋅ m; and the value for copper is 1.72 × 10⁻⁸ Ω ⋅ m. Which one of the five wires has the largest resistance?

wire A

A computer monitor uses 1.5 A of current when it is plugged into a 120 V outlet. The monitor is never turned off. What is the yearly cost of operating the monitor if the cost of electricity is $0.14/kWh?

$ 220

How much energy is stored in the combination of capacitors shown?

0.03 J

Some light bulbs are connected in parallel to a 120 V source as shown in the figure. Each bulb dissipates an average power of 60 W. The circuit has a fuse F that burns out when the current in the circuit exceeds 9 A. Determine the largest number of bulbs, which can be used in this circuit without burning out the fuse.

17

A 10.0-µF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-µF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate. How much charge flows from one capacitor to the other when the capacitors are connected?

17 μC

The figure shows a simple RC circuit consisting of a 10.0-µF capacitor in series with a resistor. Initially, the switch is open as suggested in the figure. The capacitor has been charged so that the potential difference between its plates is 100.0 V. At t = 0 s, the switch is closed. The capacitor discharges exponentially so that 2.0 s after the switch is closed, the potential difference between the capacitor plates is 37 V. In other words, in 2.0 s the potential difference between the capacitor plates is reduced to 37 % of its original value. Determine the numerical value of the resistance R.

2.0 × 10⁵ Ω ⁻⁴ ⁻⁵ ⁻⁸ ³

Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V. What is the potential drop across the 30-Ω resistor?

20 V

When two capacitors are connected in series, the equivalent capacitance of the combination is 120 µF. When the two are connected in parallel, however, the equivalent capacitance is 480 µF. What are the capacitances of the individual capacitors?

240 µF and 240 µF

A simple RC circuit consists of a 1-μF capacitor in series with a 2800-Ω resistor, a 6-V battery, and an open switch. Initially, the capacitor is uncharged. How long after the switch is closed will the voltage across the capacitor be 4.1 V?

3 × 10⁻³ s

Three parallel plate capacitors, each having a capacitance of 1.0 µF are connected in parallel. The potential difference across the combination is 100 V. What is the equivalent capacitance of this combination?

3 μF

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 25 V. What is the current through the 3.6-Ω resistor?

3.3 A

Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V. What is the equivalent resistance between the points A and B?

30 Ω

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 15 V. What amount of energy is dissipated in the 2.7-Ω resistor in 9.0 seconds?

36 J

The figure shows a circuit. The switch S can be closed on either point A or C, but not both at the same time. Use the following quantities: V1 = V2 = 12 V R1 = R4 = 1.0 Ω R2 = R3 = 2.0 Ω At what rate is energy dissipated by R1 when the switch S is closed on A?

36 W

Three resistors are connected as shown in the figure. The potential difference between points A and B is 26 V. How much current flows through the 2-Ω resistor?

4.0 A

A 3.0-A current is maintained in a simple circuit that consists of a resistor between the terminals of an ideal battery. If the battery supplies energy at a rate of 25 W, how large is the resistance?

4.2 Ω

Jason's circuit has a 24-Ω resistor that is connected in series to two 12-Ω resistors that are connected in parallel. JoAnna's circuit has three identical resistors wired in parallel. If the equivalent resistance of Jason's circuit is the same as that of JoAnna's circuit, determine the value of JoAnna's resistors.

90 Ω

A resistor dissipates 1.5 W when it is connected to a battery with a potential difference of 12 V. What is the resistance of the resistor?

96 Ω

Which one of the following statements concerning superconductors is false?

All materials are superconducting at temperatures near absolute zero kelvin

An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C₁ and C₂, with capacitances of 20.0 µF and 60.0 µF, respectively. Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. How much charge will be stored in each capacitor after a long time has elapsed?

Charge on C₁ 2.4 × 10⁻³ C Charge on C₂ 7.2 × 10⁻³ C

Two resistors are arranged in a circuit that carries a total current of 15 A as shown in the figure. Which one of the entries in the following table is correct?

Current through 2-Ω resistor 10A Voltage across 4-Ω resistor 20V

A 220-Ω resistor is connected across an ac voltage source V = (150 V) sin [2π(60 Hz)t]. What is the average power delivered to this circuit?

51 W

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 25 V. How much energy is dissipated in the 1.8-Ω resistor in 4.0 seconds?

55 J

The figure shows a circuit. The switch S can be closed on either point A or C, but not both at the same time. Use the following quantities: V1 = V2 = 12 V R1 = R4 = 1.0 Ω R2 = R3 = 2.0 Ω Determine the current through R1 when the switch S is closed on A.

6 A

Three resistors are connected as shown in the figure. The potential difference between points A and B is 26 V. How much current flows through the 3-Ω resistor?

6.0 A

Five resistors are connected as shown. What is the equivalent resistance between points A and B?

6.8 Ω

An ac current has an rms value of 3.54 A. Determine the peak value of the current

5.00 A

The figure shows a simple RC circuit consisting of a 100.0-V battery in series with a 10.0-µF capacitor and a resistor. Initially, the switch S is open and the capacitor is uncharged. Two seconds after the switch is closed, the voltage across the resistor is 37 V. How much charge is on the capacitor 2.0 s after the switch is closed?

5.2 × 10⁻⁴ C

A non-ideal battery has a 6.0-V emf and an internal resistance of 0.6 Ω. Determine the terminal voltage when the current drawn from the battery is 0.5 A.

5.7 V

Four resistors and a 6-V battery are arranged as shown in the circuit diagram. The smallest current passes through which resistor(s)?

the 60-Ω resistor

Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V. What is the current through the 30-Ω resistor?

0.7 A

A lamp uses an average power of 55 W when it is connected to an rms voltage of 120 V. Which entry in the following table is correct for this circuit?

Lamp resistance R (Ω) 260 I rms (A) 0.46

Two wires A and B are made of the same material and have the same diameter. Wire A is twice as long as wire B. If each wire has the same potential difference across its ends, which one of the following statements is true concerning the current in wire A?

The current is half as much as that in B.

The figure shows a simple RC circuit consisting of a 10.0-µF capacitor in series with a resistor. Initially, the switch is open as suggested in the figure. The capacitor has been charged so that the potential difference between its plates is 100.0 V. At t = 0 s, the switch is closed. The capacitor discharges exponentially so that 2.0 s after the switch is closed, the potential difference between the capacitor plates is 37 V. In other words, in 2.0 s the potential difference between the capacitor plates is reduced to 37 % of its original value. Calculate the electric potential energy stored in the capacitor before the switch is closed.

0.05 J

The resistivity of a silver wire with a radius of 5.04 × 10⁻⁴ m is 1.59 × 10⁻⁸ Ω ⋅ m. If the length of the wire is 3.00 m, what is the resistance of the wire?

0.0598 Ω

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. If t1 = 0.050 s, what is the value of t2? Note: The origin for the graph is not necessarily at t = 0 s.

0.067 s

A 4.5-V battery is connected to two resistors connected in series as shown in the drawing. Determine the total power dissipated in the resistors.

0.15 W

Three 15-Ω and two 25-Ω light bulbs and a 24 V battery are connected in a series circuit. What is the current that passes through each bulb?

0.25 A

Three resistors and two batteries are connected as shown in the circuit diagram. What is the magnitude of the current through the 12-V battery?

0.52 A

A 75-W and 50-W incandescent light bulbs are designed for use with the same voltage. What is the ratio of the resistance of the 75-W bulb to the resistance of the 50-W bulb?

0.67

Three resistors are connected in a circuit as shown. Using Kirchhoff's rules, determine the current in one of the 16-Ω resistors.

0.75 A

A battery is manufactured to have an emf of 24.0 V, but the terminal voltage is only 22.0 V when the battery is connected across a 10.0-Ω resistor. What is the internal resistance of the battery?

0.91 Ω

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 15 V. What is the current in the 2.7-Ω resistor?

1.2 A

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 15 V. What is the current in the 3.6-Ω resistor?

1.7 A

Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V. What is the potential drop across the 10-Ω resistor?

10 V

A 3.5-A current is maintained in a simple circuit with a total resistance of 1500 Ω. What net charge passes through any point in the circuit during a thirty second interval?

100 C

Three parallel plate capacitors, each having a capacitance of 1.0 µF are connected in parallel. The potential difference across the combination is 100 V. What is the charge on any one of the capacitors?

100 μC

Four resistors and a 6-V battery are arranged as shown in the circuit diagram. Determine the equivalent resistance for this circuit.

12 Ω

When a 1500-W hair dryer is in use, the current passing through the dryer may be represented as I = (17.7 A) sin (120πt). What is the rms current for this circuit?

12.5 A

A 4-A current is maintained in a simple circuit with a total resistance of 2 Ω. How much energy is delivered in forty five seconds?

1440 J

What is the total power dissipated in the two resistors in the circuit shown?

15 W

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. What is the resistance of the iron?

17 Ω

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. What is the peak voltage?

170 V

The figure shows a circuit. The switch S can be closed on either point A or C, but not both at the same time. Use the following quantities: V1 = V2 = 12 V R1 = R4 = 1.0 Ω R2 = R3 = 2.0 Ω What is the equivalent resistance between the points A and B?

2 Ω

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 25 V. What is the potential drop across the 3.5-Ω resistor?

2.0 V

How many electrons flow through a battery that delivers a current of 3.0 A for 12 s?

2.2 × 10²⁰

An uncharged 5.0-µF capacitor and a resistor are connected in series to a 12-V battery and an open switch to form a simple RC circuit. The switch is closed at t = 0 s. The time constant of the circuit is 4.0 s. etermine the maximum charge on the capacitor. What is the charge remaining on either plate after one time constant has elapsed?

2.2 × 10⁻⁵ C

Three resistors, 4.0-Ω, 8.0-Ω, 16-Ω, are connected in parallel in a circuit. What is the equivalent resistance of this combination of resistors?

2.3 Ω

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 25 V. What is the current through the 1.8-Ω resistor?

2.8 A

The figure shows a simple RC circuit consisting of a 100.0-V battery in series with a 10.0-µF capacitor and a resistor. Initially, the switch S is open and the capacitor is uncharged. Two seconds after the switch is closed, the voltage across the resistor is 37 V. Determine the numerical value of the resistance R.

4.3 × 10⁵ Ω

A 10.0-µF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-µF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate. How much energy is dissipated when the two capacitors are connected together?

42 μJ

A battery supplies a total charge of 5.0 μC to a circuit that consists of a series combination of two identical capacitors, each with capacitance C. Determine the charge on either capacitor.

5.0 μC

An uncharged 5.0-µF capacitor and a resistor are connected in series to a 12-V battery and an open switch to form a simple RC circuit. The switch is closed at t = 0 s. The time constant of the circuit is 4.0 s. etermine the maximum charge on the capacitor. Determine the maximum charge on the capacitor.

6.0 × 10⁻⁵ C

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. What is the rms value of the current in this circuit?

7.1 A

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 25 V. What is the equivalent resistance between the points A and B?

7.5 Ω

Determine the length of a copper wire that has a resistance of 0.172 Ω and cross-sectional area of 7.85 × 10⁻⁵ m². The resistivity of copper is 1.72 × 10⁻⁸ Ω ⋅ m.

785 m

An uncharged 5.0-µF capacitor and a resistor are connected in series to a 12-V battery and an open switch to form a simple RC circuit. The switch is closed at t = 0 s. The time constant of the circuit is 4.0 s. Determine the value of the resistance R.

8.0 × 10⁵ Ω

An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C₁ and C₂, with capacitances of 20.0 µF and 60.0 µF, respectively. Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. What is the time constant of the circuit?

8.0 × 10⁻² s

A 3.0-µF capacitor is connected in series with a 4.0-µF capacitor and a 48-V battery. What quantity of charge is supplied by the battery to charge the capacitors?

8.2 × 10⁻⁵ C

A 10.0-µF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-µF capacitor is similarly charged so that the potential difference between its plates is 5.0 V. The two charged capacitors are then connected to each other in parallel with positive plate connected to positive plate and negative plate connected to negative plate. What is the final potential difference across the plates of the capacitors when they are connected in parallel?

8.3 V

An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C₁ and C₂, with capacitances of 20.0 µF and 60.0 µF, respectively. Initially, the capacitors are uncharged; and the switch is closed at t = 0 s. Determine the total charge on both capacitors two time constants after the switch is closed.

8.3 × 10⁻³ C

Five resistors are connected as shown in the diagram. The potential difference between points A and B is 15 V. What is the equivalent resistance between the points A and B?

8.7 Ω

The figure shows variation of the current through the heating element with time in an iron when it is plugged into a standard 120 V, 60 Hz outlet. What is the approximate average power dissipated in the iron?

850 W

Which one of the following statements concerning resistors in series is true?

The current through each resistor is the same.