Q: Which of the following is NOT a possible value for the net charge $$q on an $$object, given that charge is quantized in units of the elementary charge $$e = 1.602 \times 10$$^{-19}$$\ \mathrm{C}$$? A) $$3.20 \times 10$$^{-19}$$\ \mathrm{C} B$$) $$-1.60 \times 10$$^{-19}$$\ \mathrm{C} C$$) $$-5.20 \times 10$$^{-19}$$\ \mathrm{C} D$$) $$4.80 \times 10$$^{-19}$$\ \mathrm{C}$$

C) $$-5.20 \times 10$$^{-19}$$\ \mathrm{C}$$

Question 1

Which of the following is NOT a possible value for the net charge $$q on an $$object, given that charge is quantized in units of the elementary charge $$e = 1.602 	imes 10$$^{-19}$$\ \mathrm{C}$$?

A) $$3.20 	imes 10$$^{-19}$$\ \mathrm{C}
B$$) $$-1.60 	imes 10$$^{-19}$$\ \mathrm{C}
C$$) $$-5.20 	imes 10$$^{-19}$$\ \mathrm{C}
D$$) $$4.80 	imes 10$$^{-19}$$\ \mathrm{C}$$

Accepted Answer

C) $$-5.20 	imes 10$$^{-19}$$\ \mathrm{C}$$

Question 2

Which of the following statements about electric charge is FALSE?

A) Like charges repel each other.
B) Electric charge is always conserved in a closed system.
C) Protons can be transferred between objects during charging by friction.
D) The SI unit of charge is the coulomb (C).

Accepted Answer

C) Protons can be transferred between objects during charging by friction.

Question 3

Which of the following materials is a good electrical conductor?

A) Rubber
B) Glass
C) Copper
D) Plastic

Accepted Answer

C) Copper

Question 4

Which of the following is a good electrical insulator?

A) Aluminum
B) Silver
C) Rubber
D) Iron

Accepted Answer

C) Rubber

Question 5

Which of the following materials is commonly used as a semiconductor in electronic devices?

A) Copper
B) Silicon
C) Glass
D) Gold

Accepted Answer

B) Silicon

Question 6

When a glass rod is rubbed with silk, what is the resulting charge on the glass rod and the silk, respectively?

A) Glass rod: negative, Silk: positive
B) Glass rod: positive, Silk: negative
C) Glass rod: neutral, Silk: positive
D) Glass rod: negative, Silk: neutral

Accepted Answer

B) Glass rod: positive, Silk: negative

Question 7

Sphere X has a net charge of $$6.4\ \mathrm{C}. It is $$placed in contact with a neutral identical sphere Y and then removed. Sphere Y is then placed in contact with a neutral identical sphere Z and then removed. What are the final charges on spheres X, Y, and Z, respectively?

A) $$3.2\ \mathrm{C}$$, $$1.6\ \mathrm{C}$$, $$1.6\ \mathrm{C}
B$$) $$3.2\ \mathrm{C}$$, $$3.2\ \mathrm{C}$$, $$0\ \mathrm{C}
C$$) $$1.6\ \mathrm{C}$$, $$1.6\ \mathrm{C}$$, $$3.2\ \mathrm{C}
D$$) $$0\ \mathrm{C}$$, $$3.2\ \mathrm{C}$$, $$3.2\ \mathrm{C}$$

Accepted Answer

D) $$3.2\ \mathrm{C}$$, $$1.6\ \mathrm{C}$$, $$1.6\ \mathrm{C}$$

Question 8

Which of the following best describes charging by induction?

A) Transferring electrons by rubbing two objects together
B) Bringing a charged object near a neutral conductor, causing a redistribution of charge without direct contact
C) Placing a charged object in contact with a conductor, allowing charge to flow
D) Removing electrons from an object using a magnetic field

Accepted Answer

B) Bringing a charged object near a neutral conductor, causing a redistribution of charge without direct contact

Question 9

Two point charges, $$q_1 = +0.800$$\ \mu\mathrm{C}$$ and q_2$ = -1.10\ \mu\mathrm{C}$$, are placed $$0.150\ \mathrm{m}$$ apart. What is the magnitude of the electrostatic force between them? Use $$k_e = 8.99 	imes 10^9$\ \mathrm{N}\cdot\mathrm{m}^2/\mathrm{C}^2.

A$$) $$0.352\ \mathrm{N}
B$$) $$0.528\ \mathrm{N}
C$$) $$0.176\ \mathrm{N}
D$$) $$1.05\ \mathrm{N}$$

Accepted Answer

A) $$0.352\ \mathrm{N}$$

Question 10

Three charges, each of value $$+q$$, are placed at the vertices of an equilateral triangle of side $$a. $$What is the magnitude of the net force on any one charge?

A) $$F = \frac{k_e q^2$}{a^2$}
B$$) $$F = \frac{2k_e q^2$}{a^2$}
C$$) $$F = \frac{\sqrt{3}k_e q^2$}{a^2$}
D$$) $$F = \frac{3k_e q^2$}{a^2$}$$

Accepted Answer

C) $$F = \frac{\sqrt{3}k_e q^2$}{a^2$}$$

Question 11

What is the mathematical expression for the electric field $$E at a $$distance $$r$$ from a point charge $$q$$?

A) $$E = k_e \frac{q}{r^2$}
B$$) $$E = k_e \frac{q}{r}
C$$) $$E = k_e \frac{q}{r^3$}
D$$) $$E = k_e \frac{q^2$}{r^2$}$$

Accepted Answer

A) $$E = k_e \frac{q}{r^2$}$$

Question 12

If a positive test charge is placed near a negative charge, what will happen?

A) The test charge will be repelled.
B) The test charge will be attracted.
C) The test charge will remain stationary.
D) The test charge will oscillate back and forth.

Accepted Answer

B) The test charge will be attracted.

Question 13

Where does the energy come from that increases the kinetic energy of charges as they move in an electric field?

A) The energy is supplied by the electric field itself.
B) The energy comes from the mass of the charges.
C) The energy is created by the charges as they move.
D) The energy is supplied by gravity.

Accepted Answer

A) The energy is supplied by the electric field itself.

Question 14

Which of the following statements about electric field lines is TRUE?

A) Electric field lines can cross each other.
B) Electric field lines always start on negative charges and end on positive charges.
C) The number of field lines is proportional to the magnitude of the charge.
D) Electric field lines are always parallel to the surface of a conductor.

Accepted Answer

C) The number of field lines is proportional to the magnitude of the charge.

Question 15

What is the value of the electric field inside a conductor in electrostatic equilibrium?

A) It is equal to the field outside the conductor.
B) It is zero.
C) It is infinite.
D) It depends on the shape of the conductor.

Accepted Answer

B) It is zero.

Question 16

A hollow, conducting sphere has a net charge of $$+q. $$Where does the excess charge reside?

A) Uniformly distributed throughout the volume
B) On the inner surface only
C) On the outer surface only
D) At the center of the sphere

Accepted Answer

C) On the outer surface only

Question 17

If a charge $$+q is $$placed inside a solid, neutral conducting sphere, what is the induced charge on the inner and outer surfaces, respectively?

A) Inner: $$+q$$, Outer: $$-q
B) $$Inner: $$-q$$, Outer: $$+q
C) $$Inner: $$0$$, Outer: $$+q
D) $$Inner: $$+q$$, Outer: $$0$$

Accepted Answer

B) Inner: $$-q$$, Outer: $$+q$$

Question 18

Three point charges are fixed in place as shown: $$q_1 = +7.00$$\ \mu\mathrm{C}$$ at the top, q_2$ = +5.00\ \mu\mathrm{C} at $$the lower left, and $$q_3 = +5.00$$\ \mu\mathrm{C}$$ at the lower right, each separated by 0.500$$\ \mathrm{m}$$. What is the magnitude of the net force on q_1$ due to q_2$ and q_3$?

A) 1.29$$\ \mathrm{N}$$
B) 2.58$$\ \mathrm{N}$$
C) 0.645$$\ \mathrm{N}$$
D) 3.87$$\ \mathrm{N}$$

Accepted Answer

B) $$2.58\ \mathrm{N}$$

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