Question 1

Which of the following statements best describes the process of charging by induction?

Accepted Answer

A charged object is brought near a neutral object, causing a redistribution of charges, and then the neutral object is grounded to allow charge to flow.

Question 2

A plastic rod is rubbed with fur, giving the rod a negative charge. What happens to the electrons during this process?

Accepted Answer

Electrons move from the fur to the rod.

Question 3

Which equation correctly expresses Coulomb’s Law for the magnitude of the force between two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r$$?

Accepted Answer

$$F = k_e \frac{q_1$ q_2$}{r^2$}$$

Question 4

A positively charged rod is brought near a neutral metal sphere, but does not touch it. The sphere is then grounded while the rod remains nearby. What is the final charge on the sphere after the ground connection is removed and the rod is taken away?

Accepted Answer

The sphere is left with a net negative charge.

Question 5

Which of the following best explains why a charged comb can pick up small pieces of paper?

Accepted Answer

The paper becomes polarized, and the induced charges are attracted to the comb.

Question 6

Which of the following is a key difference between the gravitational force and the electrostatic force?

Accepted Answer

Electrostatic force can be either attractive or repulsive, while gravitational force is always attractive.

Question 7

A point charge $$Q$$ creates an electric field at a distance $$r. $$What is the magnitude of the electric field at that point?

Accepted Answer

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

Question 8

Two charges, $$+2\ \mu C$$ and $$-2\ \mu C$$, are placed 1 meter apart. What is the direction of the force on the positive charge?

Accepted Answer

Toward the negative charge

Question 9

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

Accepted Answer

Electric field lines indicate the direction of the force on a positive test charge.

Question 10

A small positive test charge is placed in the electric field of a negative point charge. What is the direction of the force on the test charge?

Accepted Answer

Toward the negative charge

Question 11

If three point charges are arranged in a triangle, how do you determine the net force on one of the charges?

Accepted Answer

Add the forces as vectors using the superposition principle.

Question 12

Which of the following is true about the quantization of electric charge?

Accepted Answer

Charge is always a multiple of the elementary charge $$e.$$

Question 13

A proton and an electron are placed 1 nm apart in vacuum. Which force is stronger between them: gravitational or electric?

Accepted Answer

The electric force is stronger.

Question 14

A charged rod is brought near, but does not touch, a neutral metal sphere. The sphere is then grounded. What is the sign of the charge left on the sphere after the ground is removed and the rod is taken away?

Accepted Answer

Opposite to the rod

Question 15

Which of the following best describes the direction of the electric field produced by a positive point charge?

Accepted Answer

Away from the charge

Question 16

A $$+3\ \mu C$$ charge and a $$+6\ \mu C$$ charge are placed 2 meters apart. What is the direction of the force on the $$+3\ \mu C$$ charge?

Accepted Answer

Away from the $$+6\ \mu C$$ charge

Question 17

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

Accepted Answer

They form closed loops.

Question 18

A small test charge $$q_0 is $$placed in an electric field $$E. $$What is the force experienced by the test charge?

Accepted Answer

$$F = q_0$ E$$

Question 19

Which of the following scenarios best illustrates the superposition principle for electric fields?

Accepted Answer

The electric field at a point due to multiple charges is the sum of the fields due to each charge.

Electric Forces and Electric Fields: Fundamental Concepts and Applications

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