Circuits

A student was given five wires of the same length and diameter. The student connected the wires to the same battery one by one and measured the current through each wire. The table above shows the data collected. Which of the following can be concluded from the data?

• The wires are ohmic.

• The wires are made of different materials.

• The resistance of the wires depends on their size and shape.

• The battery has internal resistance.

Tags

NGSS.HS-PS3-5

A variable resistor is connected to a battery of unknown potential difference. The power dissipated by the resistor and the current through the resistor are measured. The figure above shows a graph of the data and a best-fit line for the data. The potential difference provided by the battery is most nearly

• 0.3 V

• 3.0 V

• 5.0 V

• 6.0 V

The figure above represents a section of a circuit containing three resistors, X, Y, and Z, of different sizes but made of the same material. Which of the following correctly ranks the current in the resistors?

• I_Z > I_X > I_Y

• I_Z = I_X > I_Y

• I_Y = I_X = I_Z

• I_Y > I_X > I_Z

The circuit shown above contains four identical lightbulbs with constant resistance, a capacitor C, which is initially uncharged, and a switch S. The switch is initially open. Which of the following correctly ranks the potential differences V₁ , V₂ , V₃ , and V₄ across the bulbs while the switch is open?

• V1 = V2 = V3 = V4

• V1 > V2 = V3 = V4

• V1 > V2 > V3 = V4

• V1 > V2 > V3 > V4

The circuit shown above contains four identical lightbulbs with constant resistance, a capacitor C, which is initially uncharged, and a switch S. The switch is initially open. Immediately after the switch is closed, the current in bulb 1 is I_a . What is the current in bulb 2 at that time?

• I_a

• (2/3)I_a

• I_a/ 2

• I_a/3

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

The circuit shown above contains four identical lightbulbs with constant resistance, a capacitor C, which is initially uncharged, and a switch S. The switch is initially open. After the switch has been closed a long time, how does the brightness of bulb 4 compare with its brightness before the switch was closed?

• Bulb 4 is much dimmer and is only barely lit.

• Bulb 4 is slightly dimmer.

• Bulb 4 is the same brightness.

• Bulb 4 is slightly brighter.

In the circuit shown above, the current through the ammeter is 20 mA and the voltmeter indicates 1.0 V. What is the current through the 40 resistor?

• 7.5 mA

• 10 mA

• 20 mA

• 40 mA

In the circuit shown above, the current through the ammeter is 20 mA and the voltmeter indicates 1.0 V. The resistance of resistor R is most nearly

• 50 Ω

• 33 Ω

• 20 Ω

• 14 Ω

In the circuit represented above, two resistors (R1 and R2 ), a capacitor C, and an open switch S are connected to a battery. The circuit reaches equilibrium. The switch is then closed, and the circuit is allowed to come to a new equilibrium. Which of the following is a true statement about the energy stored in the capacitor after the switch is closed compared with the energy stored in the capacitor before the switch is closed?

• The energy is greater.

• The energy is less.

• The energy is the same.

• The energy cannot be determined without knowing the resistances of the resistors.

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-5

Students are performing an experiment to determine how changing the area of the plates of a parallel-plate capacitor affects its behavior in a circuit. They connect a capacitor with plate area A to a battery and allow it to become fully charged. They take measurements that they believe will allow them to calculate the charge q on one plate of the capacitor. The students then repeat the procedure with other capacitors. The capacitors each have a different plate area but are otherwise identical. The students plot the calculated charge q as a function of plate area A. Their results, including a best fit to the data, are represented above. Is this graph a reasonably accurate representation of the relationship between q and A?

• Yes, because the relationship should result in a graph that is curved and decreasing.

• No, because the relationship should result in a graph that is linear and decreasing.

• No, because the relationship should result in a graph that is linear and increasing.

• No, because the relationship should result in a graph that is curved and increasing.