Q: In the circuit with a 6 V and a 9 V battery and two resistors (thirteenth image), what is the total voltage change around the loop according to Kirchhoff’s Loop Law?

$$6\,\text{V} - 4\Omega I - 9\,\text{V} - 2\Omega I = 0$$

Question 1

Which of the following best describes the behavior of conduction electrons in a metal, as shown in the first image?

Accepted Answer

Conduction electrons are bound to the solid as a whole and are free to move around.

Question 2

In the context of electrical current in metals, what is the typical relationship between the drift velocity $$v_d$$ and the random speed of conduction electrons?

Accepted Answer

The drift velocity $$v_d is $$much smaller than the random speed.

Question 3

Which equation correctly expresses the current $$I$$ through a wire in terms of the drift velocity $$v_d$$, electron charge $$e$$, number density $$n_e$$, and cross-sectional area $$A$$?

Accepted Answer

$$I = -e n_e v_d A$$

Question 4

A battery is connected to a resistor as shown in the third image. Which of the following statements is correct regarding the battery's function?

Accepted Answer

The battery provides a fixed potential difference across its terminals.

Question 5

Which symbol in the fourth image represents a capacitor?

Accepted Answer

The symbol with two parallel lines

Question 6

In the circuit with two identical bulbs in parallel (fifth image), what can be said about the brightness of bulbs A and B?

Accepted Answer

Bulbs A and B are equally bright.

Question 7

In the circuit shown in the sixth image, if all bulbs have the same resistance, which bulb will be the brightest?

Accepted Answer

The red bulb

Question 8

Which of the following circuit diagrams (seventh to eleventh images) does NOT represent a circuit with a battery and three resistors?

Accepted Answer

Diagram c

Question 9

Given the circuit in the twelfth image, what is the correct equation for the equivalent resistance $$R_{eq} of $$resistors in series?

Accepted Answer

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

Question 10

For the parallel resistors shown in the thirteenth image, what is the correct formula for the equivalent resistance $$R_{eq}$$?

Accepted Answer

$$\frac{1}{R_{eq}} = \frac{1}{R_1$} + \frac{1}{R_2$} + \cdots$$

Question 11

In the circuit with a 6 V and a 9 V battery and two resistors (thirteenth image), what is the total voltage change around the loop according to Kirchhoff’s Loop Law?

Accepted Answer

$$6\,	ext{V} - 4\Omega I - 9\,	ext{V} - 2\Omega I = 0$$

Question 12

Which of the following is the correct expression for the power dissipated in a resistor?

Accepted Answer

All of the above

Question 13

In a parallel circuit with two identical bulbs and a 120 V source, how does the power dissipated in each bulb compare to the case where the bulbs are in series with the same source?

Accepted Answer

Each bulb in parallel dissipates more power than in series.

Question 14

When the switch in the circuit with three identical bulbs (A, B, C) is closed, what happens to the brightness of bulb A?

Accepted Answer

It increases.

Question 15

In the circuit with bulbs A, B, C, and D, all identical, which bulb is the brightest?

Accepted Answer

Bulb A

Question 16

What is the main purpose of grounding a circuit, as shown in the outlet image?

Accepted Answer

To protect the circuit and ensure safety

Question 17

For a discharging capacitor in an RC circuit, which equation describes the charge $$Q on $$the capacitor as a function of time?

Accepted Answer

$$Q = Q_0$ e$$^{-t/	au}$$

Question 18

In an RC charging circuit, what is the expression for the current $$I as a $$function of time?

Accepted Answer

$$I = \frac{\varepsilon}{R} e$$^{-t/	au}$$

Electric Circuits: Current, Resistance, and Circuit Analysis Ch 28

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