AP Physics term 2

A student creates a circuit that consists of a single battery and three resistors that are arranged as shown. The battery supplies a total current of 1A. What is the potential difference across the 6Ω resistor?

2V

A student creates a circuit that consists of a single battery, three resistors, and a switch that are arranged as shown. Figure 1 shows the circuit when the switch is open and Figure 2 shows the circuit when the switch is closed. The student places three ammeters, A1 , A2 , and A3, in different locations to measure the current flowing through the circuit at those locations.

3.3 A

A student must experimentally verify Kirchhoff's loop rule to determine if the conservation of energy applies for the circuit that is shown. Which two of the following diagrams show the location and orientation in which a voltmeter should be attached in the circuit in order to collect the data necessary to verify the loop rule? Select two answers.

"anything attached to the battery or the resistor."

A circuit consists of a single battery and three resistors. Current flows from the battery and splits at the junction, as shown in the diagram. Which two of the following claims is true regarding the circuit? Select two answers.

- 10V is the sum of ΔVX and ΔVZ . - ΔVY is the same as ΔVZ .

Figures 1 and 2 are circuits that each consist of a single battery and three resistors that are arranged as shown. The potential difference across the batteries in both circuits are identical. Different locations, a through f, are indicated in the figures. Which two of the following claims are correct regarding the circuits in Figure 1 and Figure 2? Select two answers.

- The current at location aa is equal to the sum of the current that flows through locations e and f. - The current at location f is equal to the current through location aa minus the current through location c.

A circuit that consists of a single battery and four resistors are arranged as shown in the figure. Which of the following quantities correctly describe the circuit? Select two answers.

- The power dissipated by resistor RY is 8Js. - The total current that flows through the circuit is 4A.

A student creates a circuit that consists of a single battery and two resistors that are arranged as shown in the figure. What is the current that passes through the 2Ω resistor?

1 I

A circuit consists of a single battery of ΔVBattery=20V, a resistor of unknown resistance, and a motor that has an unknown constant power output. When 5A of current flows through the circuit, the motor is able to lift a 2kg block off of the ground a distance of 2m in 4s. What is the potential difference across the resistor R1 ?

18V " The power dissipated by the motor must first be taken into consideration. This will require an application of the conservation of energy. The rate at which the motor converts electromagnetic energy into mechanical energy is the power of the motor. Work done by the motor must first be determined. E = W=Fd Work= weight x distance w = 10 x 2 x 2 The rate at which work is done by the motor is the power of the motor. P=ΔEΔt P=40J/4s P=10Js This power rating can be used to determine the potential difference across the motor. P=IΔV V=P/I ΔV=(10Js)/ 5A ΔV=2V An application of Kirchhoff's loop rule must be applied to determine the potential difference across a circuit element or group of circuit elements. According to the rule, the sum of the potential difference values across each circuit element must be equal to the potential difference of the battery. Thus the potential difference across resistor R1R1 can be found by the following calculations. ΔVBattery=ΔV1+ΔVmotor ΔV1=ΔVBattery−ΔVmotor ΔV1=20V−2V ΔV1=18V'

Three resistors of known resistance R0 are arranged in the circuit that is shown. The potential difference across the battery is ΔV0. The current at point E is I0. What is the current that flows through point A?

2 I

A battery and four identical lightbulbs are connected in a circuit as shown. The rate of charge flow through Bulb 1 is I1, and the rate of charge flow through Bulbs 2, 3, and 4 are I2 , I3 , and I4, respectively. Which of the following claims are correct about the rate of charge flow throughout the circuit? Select two answers.

A The current that flows into the battery is I3+I4I3+I4. B The current that flows out of the battery is I2+I3I2+I3.

A student creates a circuit that consists of a single battery, three resistors, and a switch that are arranged as shown. Figure 1 shows the circuit when the switch is open and Figure 2 shows the circuit when the switch is closed. The student places three ammeters, A1 , A2 , and A3, in different locations to measure the current flowing through the circuit at those locations. For the circuit in Figure 1, which of the following correctly ranks the amount of current that flows through the ammeters?

A1>A2=A3

Three resistors of known resistance R0 are arranged in the circuit that is shown. The potential difference across the battery is ΔV0. If a student wanted to measure the potential difference across the resistor between points C and F, how should the student connect a voltmeter to the circuit?

Connect one end of the voltmeter to point C and the other end to point F.

Students assemble a circuit containing a battery of known potential difference that is connected in series to three resistors of different resistances. Data collected from the setup are shown in the table. Which of the following conservation laws can be verified from the data, and why?

Conservation of charge, because the current remains constant within experimental uncertainty.

A student creates a circuit that consists of a single battery and three resistors that are arranged as shown. The battery supplies a total current of 1A. The battery connected to the circuit is changed such that the total current that flows out of the battery is now 2A. Which of the following claims is correct regarding how much charge flows into the battery after the current is allowed to flow for 60s?

Exactly 120C

A circuit is designed with two resistors, R1 = 200 Ω and R2= 400 Ω, and a battery with internal resistance R = 10 Ω, as shown above. What is the relationship between the three labeled currents?

I1 = I2 = I

A student must verify the conservation of electric charge at junction J in the circuit shown in the figure. Which quantity does the student NOT have to measure to verify if charge is conserved at junction J, and why?

I4, because this current does not flow out from J.

A group of students are given a closed circuit that contains a resistor and battery that are connected in series. The students must collect data to verify the conservation of charge as it travels within an electrical circuit. What quantity must the students measure and what instrument should the students use to verify the conservation of charge?

Measure current that flows through the circuit with an ammeter.

The resistor between point B and point C is changed so that it has a resistance of 2R0. Which of the following claims is correct about the new current that flows through the resistor between point D and point E and the new current that flows out of the battery?

The current that flows through the resistor decreases, and the current that flows out of the battery decreases.

Battery VB , switch S, two ammeters, A1 and A2, and two identical resistors of resistance R0 are arranged in the circuit that is shown. Current I0 flows through ammeters when the switch S is open. Which of the following correctly predicts the current in the ammeters when the switch is closed?

The current through ammeter A1 would be 2 I 0 . "Since the potential differences across the two resistors would be the same with the switch closed, the second resistor would have the same flow rate as the first, which would double the flow rate through the battery, measured by ammeter A1."

When the circuit shown above is set up, the potential difference across the battery is 3.0 V. By how much will the magnitude of the potential difference across R2 change when R3 is removed and its branch is left open?

The magnitude of the potential difference across R2 increases by 0.5 V.

A student assembles a circuit containing three resistors with resistances R1>R2>R3 and a battery of known potential difference ΔVB, as shown in the figure. Which of the following choices correctly lists the quantities that the student must measure with a voltmeter to verify that Kirchhoff's loop rule applies throughout the circuit?

The potential difference across the battery, R1, R2, and R3

A student creates a circuit that consists of a single battery, three resistors, and a switch that are arranged as shown. Figure 1 shows the circuit when the switch is open and Figure 2 shows the circuit when the switch is closed. The student places three ammeters, A1 , A2 , and A3, in different locations to measure the current flowing through the circuit at those locations. Which of the following claims is correct about how ΔV3 , the potential difference across the resistor connected to A3, changes when the switch is closed?

The potential difference ΔV3ΔV3 is greater when the switch is closed, as in Figure 2.

A battery ΔV, a switch S, and two identical lightbulbs, B1 and B2, are connected in the circuit that is shown. The switch is initially closed and current flows through the circuit. Which of the following correctly predicts how the brightness of the lightbulbs changes when the switch is opened compared with when the switch is closed?

The removal of B2 from the circuit does not affect the current through B1 , so the brightness of B1B1 does not change.

A student creates a circuit that consists of a single battery and three resistors that are arranged as shown. The battery supplies a total current of 1A. Which of the following claims is correct regarding the current that flows through the different branches of the circuit?

The total current that flows through the 6Ω resistor and 3Ω resistor in the parallel branches is equal to the current that flows through the battery.

A student creates a circuit that consists of a single battery and three resistors of unknown resistances that are arranged as shown. Which of the following procedures can the student use to verify the law of conservation of energy in the circuit?

Use a voltmeter to measure the potential difference across the battery and each resistor.

A student must determine if electric charge is conserved in the circuit shown in the figure. Which of the following procedures could the student perform to make the determination, and why?

Use an ammeter to measure the amount of current that flows through each circuit element in the circuit, because current is defined as the amount of charge that passes through a cross-sectional area per unit of time.

A circuit consists of a single battery and three resistors that are arranged as shown. How does the power Pz dissipated by resistor Rz compare to the power Py dissipated by resistor Ry?

ΔPz=4ΔPY "RZ receives the total current that travels through the circuit. Since RX and RY have the same resistance, the total current splits at the junction such that each branch receives half of the total current. The power dissipated can be found using P=IΔV, which can be reexpressed as P=I^2R. The resistance for both resistors is the same, so the current that flows through the circuit should be considered. Since P∼I^2, RZ receives double the current as RY, which means that the rate of energy dissipation will be four times larger for RZ compared to RY."