Q: A $$-1.0 \times 10$$^{-6}$$ C charge is placed in a uniform electric field of 2.0$$ \times $$10^4 N/C $$directed to the right. What is the direction and magnitude of the force on the charge?

To the left, $$2.0 \times 10$$^{-2}$$ N

Question 1

A proton is placed 0.02 m away from a stationary point charge of $$+2.0 	imes 10$$^{-6}$$ C. What is the magnitude of the electric force experienced by the proton? (Use k = 8.99$$ 	imes $$10^9 N m$^2/C$^2$$, $$q_{proton} = +1.6 	imes 10$$^{-19}$$ C)

Accepted Answer

$$7.19 	imes 10$$^{-11}$$ N

Question 2

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

Accepted Answer

Electric field lines are always perpendicular to equipotential lines.

Question 3

A $$-3.0 	imes 10$$^{-9}$$ C charge is placed at the origin. What is the electric potential at a point 0.05 m away from the charge? (Use k = 8.99$$ 	imes $$10^9 N m$^2/C$^2)$$

Accepted Answer

$$-539 V$$

Question 4

Two parallel plates are separated by 0.01 m and have a potential difference of 120 V. What is the magnitude of the electric field between the plates?

Accepted Answer

$$1.2 	imes 10^3$ V/m

Question 5

A neutral metal sphere is brought near a negatively charged rod. What happens to the charges in the sphere?

Accepted Answer

Negative charges in the sphere move away from the rod, leaving the near side positively charged.

Question 6

If the electric potential at point A is 50 V and at point B is 20 V, what is the change in electric potential energy when a $$+2.0 	imes 10$$^{-6}$$ C charge moves from A to B?

Accepted Answer

$$-6.0 	imes 10$$^{-5}$$ J

Question 7

Which of the following best describes the direction of the electric field at a point near a negative point charge?

Accepted Answer

Radially inward toward the charge

Question 8

A $$+1.0 	imes 10$$^{-6}$$ C charge and a -2.0$$ 	imes $$10^{-6} C $$charge are separated by 0.10 m. What is the magnitude of the electric force between them?

Accepted Answer

$$1.80 N$$

Question 9

Which of the following is true about the electric potential due to a collection of point charges?

Accepted Answer

The total potential is the sum of the individual potentials at that point.

Question 10

A $$+3.0 	imes 10$$^{-9}$$ C charge is moved from a point where the potential is 100 V to a point where the potential is 40 V. What is the change in electric potential energy?

Accepted Answer

$$-1.8 	imes 10$$^{-7}$$ J

Question 11

Which of the following best explains why a charged balloon can stick to a neutral wall?

Accepted Answer

The charged balloon induces a separation of charges in the wall, causing attraction.

Question 12

If the distance between two point charges is doubled, what happens to the magnitude of the electric force between them?

Accepted Answer

It becomes one fourth as large.

Question 13

A $$-1.0 	imes 10$$^{-6}$$ C charge is placed in a uniform electric field of 2.0$$ 	imes $$10^4 N/C $$directed to the right. What is the direction and magnitude of the force on the charge?

Accepted Answer

To the left, $$2.0 	imes 10$$^{-2}$$ N

Question 14

Which of the following is a correct statement of Newton's Third Law as it applies to electric forces?

Accepted Answer

The force on $$q_1$$ due to $$q_2 is $$equal in magnitude and opposite in direction to the force on $$q_2$$ due to $$q_1.$$

Question 15

A $$+2.0 	imes 10$$^{-6}$$ C charge is placed at the center of a circle of radius 0.10 m. What is the magnitude of the electric field at a point on the circle?

Accepted Answer

$$1.80 	imes 10^5$ N/C

Question 16

Which of the following is true about equipotential lines?

Accepted Answer

No work is required to move a charge along an equipotential line.

Question 17

A $$+1.0 	imes 10$$^{-6}$$ C charge is moved 0.02 m in the direction of a uniform electric field of 5.0$$ 	imes $$10^3 N/C. $$What is the change in electric potential energy?

Accepted Answer

$$-1.0 	imes 10$$^{-5}$$ J

Question 18

Which of the following best describes the relationship between electric field and electric potential?

Accepted Answer

The electric field is the negative gradient of the electric potential.

Question 19

A $$+1.0 	imes 10$$^{-6}$$ C charge and a +2.0$$ 	imes $$10^{-6} C $$charge are placed 0.05 m apart. What is the electric potential at the midpoint between them?

Accepted Answer

$$7.19 	imes 10^4$ V

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