Question 1

Which equation correctly expresses Ohm's Law for a resistor?

Accepted Answer

$$V = IR$$

Question 2

A battery with emf $$\varepsilon$$ and internal resistance $$r is $$connected to a resistor $$R. $$What is the terminal voltage $$V_{ab}$$ across the battery?

Accepted Answer

$$V_{ab} = \varepsilon - Ir$$

Question 3

In a circuit, how should you connect an ammeter and a voltmeter to measure the current through and the voltage across a resistor simultaneously?

Accepted Answer

An ammeter in series and a voltmeter in parallel.

Question 4

What is the equivalent resistance $$R_{eq} of $$three resistors $$R_1$$, $$R_2$$, and $$R_3$$ connected in series?

Accepted Answer

$$R_{eq} = R_1$ + R_2$ + R_3$

Question 5

For two resistors $$R_1$$ and $$R_2 in $$parallel, what is the correct formula for the equivalent resistance $$R_{eq}$$?

Accepted Answer

$$R_{eq} = \frac{R_1$ R_2$}{R_1$ + R_2$}$$

Question 6

A circuit contains a battery ($$\varepsilon = 18\,\mathrm{V}$$, $$r = 0$$), a $$4\,\Omega$$ resistor in series with a parallel combination of $$6\,\Omega$$ and $$3\,\Omega$$ resistors. What is the equivalent resistance $$R_{eq} of $$the network?

Accepted Answer

$$R_{eq} = 6\,\Omega$$

Question 7

Which law states that the sum of the currents entering a junction equals the sum of the currents leaving the junction?

Accepted Answer

Kirchhoff's Junction (Current) Law

Question 8

In a series circuit, what is true about the current through each resistor?

Accepted Answer

The current is the same through each resistor.

Question 9

A $$12\,\mathrm{V}$$ battery with internal resistance $$2\,\Omega$$ supplies a current of $$2\,\mathrm{A}. $$What is the power dissipated in the internal resistance?

Accepted Answer

$$8\,\mathrm{W}$$

Question 10

Which formula gives the power $$P$$ delivered to a circuit element with voltage $$V_{ab}$$ and current $$I$$?

Accepted Answer

$$P = V_{ab} I$$

Question 11

In an RC circuit, what is the time constant $$	au$$ for a resistor $$R$$ and capacitor $$C$$?

Accepted Answer

$$	au = RC$$

Question 12

When charging a capacitor in an RC circuit, which factors affect the rate at which the capacitor charges?

Accepted Answer

The emf of the battery, the capacitance, and the resistance.

Question 13

A capacitor is discharging through a resistor. What is the equation for the voltage across the capacitor as a function of time?

Accepted Answer

$$V(t) = V_0$ e$$^{-t/RC}$$

Question 14

In a parallel circuit, what is true about the voltage drop across each resistor?

Accepted Answer

The voltage drop is the same across each resistor.

Question 15

If a string of holiday lights is wired in series and one bulb burns out, what happens?

Accepted Answer

The entire set of lights stops working.

Question 16

Which of the following best describes the behavior of capacitors in a DC circuit after a long time?

Accepted Answer

They behave like open circuits.

Question 17

What is the correct formula for the equivalent capacitance $$C_{eq} of $$two capacitors $$C_1$$ and $$C_2 in $$series?

Accepted Answer

$$\frac{1}{C_{eq}} = \frac{1}{C_1$} + \frac{1}{C_2$}$$

Question 18

A $$6\,\Omega$$ resistor dissipates $$24\,\mathrm{W} of $$power. What is the current through the resistor?

Accepted Answer

$$2\,\mathrm{A}$$

Question 19

Which statement about the sum of potential differences around a closed loop in a circuit is correct?

Accepted Answer

The sum equals zero.

Direct-Current Circuits: Resistance, EMF, and Circuit Analysis

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