$$k = 8.988 \times 10^9$\ \mathrm{N \cdot m^2$ / C^2$}$$

Question 1

Which of the following statements best describes the conservation of electric charge?

Accepted Answer

The arithmetic sum of the total charge in any interaction remains constant.

Question 2

A neutral atom becomes negatively charged when:

Accepted Answer

It gains electrons.

Question 3

Which of the following materials is most likely to be a good conductor?

Accepted Answer

Copper

Question 4

A metal rod is brought near a neutral metal sphere and then removed without touching. The sphere is found to be charged. This process is called:

Accepted Answer

Induction

Question 5

According to Coulomb’s Law, the force between two point charges $$Q_1$$ and $$Q_2$$ separated by a distance $$r is $$given by:

Accepted Answer

$$F = k \frac{Q_1$ Q_2$}{r^2$}$$

Question 6

What is the value of the proportionality constant $$k in $$Coulomb’s Law?

Accepted Answer

$$k = 8.988 	imes 10^9$\ \mathrm{N \cdot m^2$ / C^2$}$$

Question 7

The electric field $$\vec{E} at a $$distance $$r$$ from a point charge $$Q is$$:

Accepted Answer

$$E = k \frac{Q}{r^2$}$$

Question 8

Which of the following best describes the direction of electric field lines?

Accepted Answer

They start on positive charges and end on negative charges.

Question 9

A parallel plate capacitor has two closely spaced, oppositely charged plates. The electric field between the plates is:

Accepted Answer

Constant in magnitude and direction.

Question 10

The electric flux $$\Phi_E$$ through a surface is given by:

Accepted Answer

$$\Phi_E = EA \cos 	heta$$

Question 11

Gauss’s Law relates the net electric flux through a closed surface to:

Accepted Answer

The total charge enclosed by the surface.

Question 12

Which of the following is true about the electric field inside a conductor in electrostatic equilibrium?

Accepted Answer

It is zero.

Question 13

A DNA molecule’s double helix structure is stabilized by:

Accepted Answer

Electrostatic attraction between A-T and G-C base pairs.

Question 14

A photocopy machine uses electrostatics to transfer toner to paper. Which part of the process relies on the attraction of charged particles?

Accepted Answer

Only black areas stay charged and attract toner particles.

Question 15

If three point charges are placed at the corners of a triangle, the net force on one charge is found by:

Accepted Answer

Adding the forces vectorially from the other two charges.

Question 16

Which of the following is NOT a property of electric field lines?

Accepted Answer

They cross each other at points of equal field strength.

Question 17

A nonconductor is brought near a charged rod. What happens?

Accepted Answer

The nonconductor experiences charge separation (polarization).

Question 18

The charge of a single electron is:

Accepted Answer

$$1.602 	imes 10$$^{-19}$$\ \mathrm{C}$$

Question 19

Which of the following best describes the process of charging by conduction?

Accepted Answer

A charged object touches another object, transferring charge.

Question 20

The superposition principle for electric fields states that:

Accepted Answer

The total electric field is the sum of the individual fields from all charges.

Chapter 16: Electric Charge and Electric Field – Study Notes

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