Physics Chapter 18

If the potential difference across a pair of batteries used to power a flashlight is 6.0 V, what is the potential difference across the flashlight bulb?

6.0 V

Three resistors connected in parallel have individual values of 4.0 , 6.0 , and 10.0 , as shown below. If this combination is connected in series with a 12.0 V battery and a 2.0 resistor, what is the current in the 10.0 resistor?

0.58 A

Three resistors with values of 3.0 , 6.0 , and 12 are connected in parallel. What is the equivalent resistance of this combination?

1.7 Ω

What is the equivalent resistance of the resistors in the figure shown below?

10

Three resistors with values of 4.0 , 6.0 , and 8.0 , respectively, are connected in series. What is their equivalent resistance?

18

Two resistors with values of 6.0 and 12 are connected in parallel. This combination is connected in series with a 4.0 resistor. What is the equivalent resistance of this combination?

8.0 Ω

How does the potential difference across the bulb in a flashlight compare with the terminal voltage of the batteries used to power the flashlight?

It = I1 = I2 = I3

Three resistors with values of R1, R2, and R3 are connected in parallel. Which of the following expresses the total resistance, Req, of the three resistors?

Req = R1 + R2 + R3

A circuit is composed of resistors wired in series. What is the relationship between the equivalent resistance of the circuit and the resistance of the individual resistors?

The equivalent resistance is equal to the sum of the individual resistances.

Two resistors having the same resistance value are wired in parallel. How does the equivalent resistance compare to the resistance value of a single resistor?

The equivalent resistance is half the value of a single resistor.

What happens when the switch is closed in the circuit shown below?

The lamp goes out, because the battery terminals connect to each other.

How does the potential difference across the bulb in a flashlight compare with the terminal voltage of the batteries used to power the flashlight?

The potential difference is equal to the terminal voltage.

Which of the following statements about a battery as a source of electric current is not true?

The terminal voltage of a battery is equal to its emf.

Three resistors connected in parallel carry currents labeled I1, I2, and I3. Which of the following expresses the total current It in the combined system?

V=V1+v2+v3

Three resistors connected in series have potential differences across them labeled V1, V2, and V3. Which of the following expresses the potential difference taken over the three resistors together?

V=V1+v2+v3

Three resistors connected in parallel have potential differences across them labeled V1, V2, and V3. Which of the following expresses the potential difference across all three resistors?

Vt = V1 + V2 + V3

A circuit has a continuous path through which charge can flow from a voltage source to a device that uses electrical energy. What is the name of this type of circuit?

a closed circuit

In any complex resistance circuit, the voltage across any resistor in the circuit is always

equal to or less than the voltage source.

What is the equivalent resistance for the resistors in the figure shown above?

equal to or less than the voltage source.

To find the current in a complex circuit, it is necessary to know the

equivalent resistance of the circuit.

Which of the following is the best description of a schematic diagram?

shows the parts of a circuit and how the parts connect to each other

The equivalent resistance of a complex circuit is usually determined by

simplifying the circuit into groups of series and parallel circuits.