### Multiple Choice

### 19.1 Ohm's law

- $\text{C/s}$
- $\text{e/s}$
- $-\text{e}/\text{s}$
- ${\text{C/s}}^{2}$

- $\text{C/m}$
- $\text{C/s}$
- $\mathrm{\Omega}$
- $\mathrm{\Psi}$

The equivalent unit for an ohm is a ________.

- V/A
- C/m
- $$\frac{\text{A}}{\text{V}}$$
- V/s

- 1
- $\frac{1}{2}$
- 4
- 2

### 19.2 Series Circuits

What does the circuit element shown represent?

- a battery
- a capacitor
- the ground
- a switch

How many 10-Ω resistors must be connected in series to make an equivalent resistance of 80 Ω?

- 80
- 8
- 20
- 40

Which two circuit elements are represented in the circuit diagram?

- a battery connected in series with an inductor
- a capacitor connected in series with a resistor
- a resistor connected in series with a battery
- an inductor connected in series with a resistor

How much current will flow through a 10-V battery with a 100-Ω resistor connected across its terminals?

- 0.1 A
- 1.0 A
- 0
- 1,000 A

### 19.3 Parallel Circuits

A 10-Ω resistor is connected in parallel to another resistor R . The equivalent resistance of the pair is 8 Ω. What is the resistance R?

- 10 Ω
- 20 Ω
- 30 Ω
- 40 Ω

Are the resistors shown connected in parallel or in series? Explain.

- The resistors are connected in parallel because the same current flows through all three resistors.
- The resistors are connected in parallel because different current flows through all three resistors.
- The resistors are connected in series because the same current flows through all three resistors.
- The resistors are connected in series because different current flows through all three resistors.

### 19.4 Electric Power

- $$P={I}^{2}R$$
- $P=\frac{V}{{R}^{2}}$
- $$P=IV$$
- $P=\frac{{V}^{2}}{R}$

- $$0.36\phantom{\rule{thinmathspace}{0ex}}\text{W}$$
- $0.011\phantom{\rule{thinmathspace}{0ex}}\text{W}$
- Voltage drop across is $5\phantom{\rule{thinmathspace}{0ex}}\text{V}$.
- $2.5\phantom{\rule{thinmathspace}{0ex}}\text{W}$

- A resistor dissipates power in the form of heat.
- A resistor dissipates power in the form of sound.
- A resistor dissipates power in the form of light.
- A resistor dissipates power in the form of charge.

What power is dissipated in a circuit through which 0.12 A flows across a potential drop of 3.0 V?

- 0.36 W
- 0.011 W
- 5 V
- 2.5 W