Q: A proton has a mass of $$1.67 \times 10$$^{-27}$$ kg and a charge of 1.6$$ \times $$10^{-19} C. $$What is the charge-to-mass ratio of a proton?

$$9.58 \times 10$$^{7}$$ \ \mathrm{C/kg}$$

Q: Which of the following statements is true regarding the relative strength of electrical and gravitational forces between a proton and an electron?

The electrical force is approximately $$2.6 \times 10$$^{39}$$ times stronger than the gravitational force.

Question 1

Which of the following best explains why lightning occurs during a thunderstorm?

Accepted Answer

The collision of water droplets causes a separation of electric charge, creating a large potential difference between the cloud and the ground, which is discharged as lightning.

Question 2

A proton has a mass of $$1.67 	imes 10$$^{-27}$$ kg and a charge of 1.6$$ 	imes $$10^{-19} C. $$What is the charge-to-mass ratio of a proton?

Accepted Answer

$$9.58 	imes 10$$^{7}$$ \ \mathrm{C/kg}$$

Question 3

Which statement about electric charge is correct?

Accepted Answer

Electric charge occurs in discrete multiples of the elementary charge $$e = 1.6 	imes 10$$^{-19}$$ C.

Question 4

A neutral atom becomes a positive ion when:

Accepted Answer

It loses one or more electrons.

Question 5

When a negatively charged comb is brought near small pieces of paper, the paper is attracted to the comb. What is the best explanation for this phenomenon?

Accepted Answer

The negative charge on the comb induces a positive charge on the side of the paper closest to the comb, resulting in attraction.

Question 6

Which of the following best describes the distribution of charge on a conductor?

Accepted Answer

Excess charge resides on the surface of a conductor and is distributed as far apart as possible.

Question 7

According to Coulomb’s Law, what happens to the force between two point charges if the distance between them is doubled?

Accepted Answer

The force decreases by a factor of 4.

Question 8

Which of the following statements is true regarding the relative strength of electrical and gravitational forces between a proton and an electron?

Accepted Answer

The electrical force is approximately $$2.6 	imes 10$$^{39}$$ times stronger than the gravitational force.

Question 9

Which material is most likely to be a good electrical conductor?

Accepted Answer

Copper

Question 10

A parallel-plate capacitor is used to model the membrane of a nerve cell. If the area of the plates is doubled while the separation remains constant, what happens to the capacitance?

Accepted Answer

The capacitance doubles.

Question 11

Which of the following best describes the function of a dielectric in a capacitor?

Accepted Answer

It increases the capacitance by reducing the electric field between the plates.

Question 12

Which equation correctly expresses Ohm’s Law?

Accepted Answer

$$R = \frac{V}{I}$$

Question 13

A light bulb is connected to a 12 V battery and draws a current of 2 A. What is the resistance of the bulb?

Accepted Answer

$$6\ \Omega$$

Question 14

Which of the following is a correct statement about superconductors?

Accepted Answer

Superconductors have zero electrical resistance below a certain critical temperature.

Question 15

Which of the following is NOT a consequence of the interaction between electricity and magnetism?

Accepted Answer

A stationary electric charge experiences a force in a magnetic field.

Question 16

Which of the following best explains why the north pole of a compass needle points toward the geographic North Pole?

Accepted Answer

The geographic North Pole is actually the magnetic south pole of the Earth.

Question 17

Which of the following is responsible for the colors observed in aurorae?

Accepted Answer

Excitation and ionization of atmospheric nitrogen and oxygen by energetic electrons from the Sun.

Question 18

A generator converts which type of energy into electrical energy?

Accepted Answer

Mechanical energy

Question 19

Which of the following best describes the Earth's magnetosphere?

Accepted Answer

It is a region around the Earth where the magnetic field deflects solar wind particles.

Electricity and Magnetism: Fundamental Concepts and Applications

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