Short Answer
19.1 Ohm's law
True or falseâ€”it is possible to produce nonzero DC current by adding together AC currents.
 false
 true
What type of current is used in cars?
 alternating current
 indirect current
 direct current
 straight current

C = Bg

g = BC

\frac{B}{C} = \frac{C}{g}

B = Cg

Ohmâ€™s law says that the current through a resistor equals the voltage across the resistor multiplied by the resistance of the resistor.

Ohmâ€™s law says that the voltage across a resistor equals the current through the resistor multiplied by the resistance of the resistor.

Ohmâ€™s law says that the resistance of the resistor equals the current through the resistor multiplied by the voltage across a resistor.

Ohmâ€™s law says that the voltage across a resistor equals the square of the current through the resistor multiplied by the resistance of the resistor.
What is the current through a 100Î© resistor with 12 V across it?
 0
 0.12 A
 8.33 A
 1,200 A

0.017

1

60

120
19.2 Series Circuits
Given a circuit with one 9V battery and with its negative terminal connected to ground. The two paths are connected to ground from the positive terminal: the right path with a 20Î© and a 100Î© resistor and the left path with a 50Î© resistor. How much current will flow in the right branch?
 $$\frac{\text{9}}{\text{120}}$$
 $$\frac{\text{9}}{\text{100}}$$
 $$\frac{\text{9}}{\text{50}}$$
 $$\frac{\text{9}}{\text{20}}$$
Through which branch in the circuit below does the most current flow?

All of the current flows through the left branch due to the open switch.

All of the current flows through the right branch due to the open switch in the left branch.

All of the current flows through the middle branch due to the open switch in the left branch

There will be no current in any branch of the circuit due to the open switch.
What current flows through the 75\text{}\Omega resistor in the circuit below?

0.072\,\text{A}

0.12\,\text{A}

0.18\,\text{A}

0.3\,\text{A}

6.8 Î©

12 Î©

36 Î©

72 Î©
19.3 Parallel Circuits
Ten 100Î© resistors are connected in series. How can you increase the total resistance of the circuit by about 40 percent?
 Adding two 10Î© resistors increases the total resistance of the circuit by about 40 percent.
 Removing two 10Î© resistors increases the total resistance of the circuit by about 40 percent.
 Adding four 10Î© resistors increases the total resistance of the circuit by about 40 percent.
 Removing four 10Î© resistors increases the total resistance of the circuit by about 40 percent.

The current and the voltage remain the same.

The current decreases and the voltage remains the same.

The current and the voltage increases.

The current increases and the voltage remains the same.
In the circuit shown, through which resistor(s) does the most current flow? Through which does the least flow? Explain.
 The most current flows through the 15Î© resistor because all the current must pass through this resistor.
 The most current flows through the 20Î© resistor because all the current must pass through this resistor.
 The most current flows through the 25Î© resistor because it is the highest resistance.
 The same current flows through the all the resistor because all the current must pass through each of the resistors.
19.4 Electric Power
You want to increase the power dissipated in a circuit. You have the choice between doubling the current or doubling the resistance, with the voltage remaining constant. Which one would you choose?
 doubling the resistance
 doubling the current
You want to increase the power dissipated in a circuit. You have the choice between reducing the voltage or reducing the resistance, with the current remaining constant. Which one would you choose?
 reduce the voltage to increase the power
 reduce the resistance to increase the power
What power is dissipated in the circuit consisting of 310Î© resistors connected in series across a 9.0V battery?
 The power dissipated is 2430 W.
 The power dissipated is 270 W.
 The power dissipated is 2.7 W.
 The power dissipated is 0.37 W.
What power is dissipated in a circuit consisting of three 10Î© resistors connected in parallel across a 9.0V battery?
 The power dissipated is 270 W.
 The power dissipated is 30 W.
 The power dissipated is 24 W.
 The power dissipated is 1/24 W.