Question 1

Which of the following statements about electric current is NOT correct?

Accepted Answer

In most electric circuits, electrons are moving in the direction parallel to that of the associated electric current.

Question 2

A wire resistor has resistivity $$\rho$$, length $$L$$, and cross-sectional area $$A. $$Which of the following statements is true?

Accepted Answer

None of the above statements is true.

Question 3

Two identical batteries with emf $$\mathcal{E}$$ are connected in series with a single resistor $$R. If$$ $$V = 0\ \mathrm{V} is $$defined at the negative terminal of the lower battery, what is the correct ranking of the electric potentials $$V_A, V_B, V_C, V_D, V_E$$ from highest to lowest, assuming ideal wires?

Accepted Answer

$$V_A \u003e V_B = V_C \u003e V_D = V_E$$

Question 4

A graph shows the current $$I$$ versus potential difference $$\Delta V$$ for a conductor with non-zero resistance. Which statement is true?

Accepted Answer

The resistance below $$\Delta V = V' is $$given by the slope of the straight-line segment.

Question 5

A cylindrical wire resistor with radius $$R$$ and length $$L is $$connected to a battery with emf $$\mathcal{E}$$, generating heat. If both the radius and length are increased by a factor of 2, which of the following statements correctly describes the change in resistance and heat?

Accepted Answer

Neither of them is true.

Question 6

In the circuit shown, which of the following statements is NOT true?

Accepted Answer

Resistor $$R_1 is $$connected to combined resistor $$R_2$$-$$R_3 in $$parallel.

Question 7

A resistor of resistance $$R$$ and a capacitor of capacitance $$C$$ are connected in series to a battery of voltage $$V. If a $$switch is closed at $$t = 0$$, the charge stored in the capacitor as a function of time is $$Q(t) = CV (1 - e$$^{-t/	au}$$). $$Which statement is true?

Accepted Answer

None of the above statements is true.

Question 8

Given the following equations for a circuit with $$R_1$$ = $$R_2$$ = $$R_3 = 100$$\ \Omega$$:

$$\begin{align*}
(1)\quad & $$I_1$$ - $$I_2$$ - $$I_3 = 0$$ \
(2)\quad & 15\mathrm{V} - $$I_2$$ 	imes 100\Omega - $$I_1$$ 	imes 100\Omega = 0 \
(3)\quad & 15\mathrm{V} - 9\mathrm{V} - $$I_3$$ 	imes 100\Omega - $$I_1$$ 	imes 100\Omega = 0
\end{align*}$$

If $$($$I_1$$, $$I_2$$, $$I_3) = (0.07$$\ \mathrm{A}, 0.08\ \mathrm{A}, -0.01\ \mathrm{A})$$, which statement is NOT true?

Accepted Answer

The electric potential difference across $$R_2 is $$the same as that across $$R_3.$$

Question 9

Three particles travel through a region of space where the magnetic field is out of the page. Based on their paths, what are the signs of the charges of these three particles?

Accepted Answer

1 is neutral, 2 is negative, and 3 is positive.

Question 10

A wire is placed between the poles of a horseshoe magnet (left is north, right is south). When the switch is closed in the circuit, which way will the wire between the poles initially deflect?

Accepted Answer

downward

Question 11

A charged particle is moving in a static uniform magnetic field. Which of the following is true about the particle's speed?

Accepted Answer

True: Its speed will not change.

Question 12

If you cut a straight bar magnet in half (with the south pole on the left and the north pole on the right), what will be the polarity of the left piece?

Accepted Answer

True: The left piece will have a south pole on its left end and a north pole on its right end.

Question 13

Kirchhoff’s junction rule follows from the conservation of energy.

Accepted Answer

False

Question 14

If capacitors are connected in parallel to a battery, do they all store the same amount of charge?

Accepted Answer

False

Question 15

An electron moving through a region of uniform magnetic field gains kinetic energy due to the magnetic force.

Accepted Answer

False

Question 16

A real-world application: In MRI machines, strong uniform magnetic fields are used. If a proton moves perpendicular to the field, what is the nature of its path and does its speed change?

Accepted Answer

It moves in a circle at constant speed.

Question 17

A $$10\ \Omega$$ resistor and a $$20\ \Omega$$ resistor are connected in parallel across a $$12\ \mathrm{V}$$ battery. What is the total current supplied by the battery?

Accepted Answer

$$1.8\ \mathrm{A}$$

Question 18

A $$5\ \mu\mathrm{F}$$ and a $$10\ \mu\mathrm{F}$$ capacitor are connected in series to a $$100\ \mathrm{V}$$ battery. What is the total charge stored on the series combination?

Accepted Answer

$$3.33 	imes 10$$^{-4}$$\ \mathrm{C}$$

Question 19

A wire of length $$L$$ and cross-sectional area $$A is $$made of a material with resistivity $$\rho. If $$the wire is stretched to twice its original length without changing its volume, what happens to its resistance?

Accepted Answer

It increases by a factor of 4.

Question 20

A $$2\ \Omega$$ resistor and a $$4\ \Omega$$ resistor are connected in series to a $$12\ \mathrm{V}$$ battery. What is the voltage drop across the $$4\ \Omega$$ resistor?

Accepted Answer

$$8\ \mathrm{V}$$

PHYS 113 - Introduction to Physics II: Review 3 – Step-by-Step Study Guidance

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