Chapter 21: Electric Fields Practice Test
 1. In a Millikan oil drop experiment, a drop has been found to weigh 1.92 × 10-14 N. When the electric field is 3.0 × 104 N/C, the drop is suspended motionless. What is the charge on the oil drop?
 a. 5.8 × 10-19 C b. 6.4 × 10-19 C c. 6.4 × 1019 C d. 5.8 × 10-10 C
 2. An electric field is about 150 N/C downward. What is the direction of the force on a positively-charged particle?
 a. stationary b. downward c. changes rapidly d. upward
 3. The electric field at the location of q' is represented by which of the following equations?
 a. E= q/ΔV b. E= W/q' c. E= F/q' d. E= q'/Fq'
 4. Two parallel plates are given opposite charges. A voltmeter measures the electric potential difference to be 47.0 V. The plates are 5.0 cm apart. What is the magnitude of the electric field between them?
 a. 1.1 × 10-3 N/C b. 9.4 × 102 N/C c. 9.4 × 103 N/C d. 1.1 × 10-4 N/C
 5. An electric field is to be measured using a positive test charge of 3.0 × 10-5C. This test charge experiences a force of 0.50 N acting at an angle of 15 degrees. What is the magnitude of the electric field at the location of the test charge?
 a. 1.7 × 103 N/C b. 6.0 × 10-5 N/C c. 0.49 N/C d. 1.7 × 104 N/C
 6. The SI derived unit of potential difference is the __________.
 a. joule b. volt c. coulomb d. ohm
 7. As a positive test charge moves farther from a positive charge in an electric field, the potential energy __________.
 a. remains the same b. doubles c. decreases d. increases
 8. A 6.4-ΜF capacitor is first charged so that the electric potential difference is 5.0 V. How much additional charge is needed to increase the electric potential difference to 12.0 V?
 a. 7.7 × 10-5 C b. 7.7 × 105 C c. 4.5 × 105 C d. 4.5 × 10-5 C
 9. The __________ is a vector quantity that relates the force on a test charge to the size of the charge.
 a. electric field b. potential c. equipotential d. capacitor
 10. A negative charge of 1.5 × 10-7 C experiences a force of 0.030 N to the right in an electric field. What is the magnitude and direction of the field?
 a. 4.5 × 10-7 N/C directed to the right b. 2.0 × 105 N/C directed to the right c. 2.0 × 105 N/C directed to the left d. 4.5 X10-9 N/C directed to the left