PASSPOINTPRO
PHYS 112
GENERAL PHYSICS II
CAPACITANCE & DIELECTRICS
100-QUESTION PRACTICE TEST
Answers, calculations & detailed explanations after every question
100 70+ A-D
QUESTIONS CALCULATIONS FORMAT
Capacitance • Parallel Plates • Dielectrics • Series & Parallel • Energy • Breakdown
, FORMULA REFERENCE
C = Q/V | Q = CV | V = Q/C
Parallel plates: C = k epsilon_0 A/d
Parallel: C_eq = C1 + C2 + ...
Series: 1/C_eq = 1/C1 + 1/C2 + ...
Energy: U = (1/2)CV^2 = Q^2/(2C) = (1/2)QV
Uniform field: E = V/d
Dielectric inserted fully: C = kC0
Battery connected: V constant; Q and U increase with k
Battery disconnected: Q constant; V and U decrease by k
Vacuum permittivity: epsilon_0 = 8.854 x 10^-12 F/m
Coverage: capacitance fundamentals, parallel-plate geometry, dielectric behavior, series/parallel networks, energy storage, electric fields, and
dielectric breakdown.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 2
, 1. A capacitor of 2.2 uF is connected across a 12 V source. What charge is stored on either
plate?
A. 26.4 uC
B. 13.2 uC
C. 264 uC
D. 52.8 uC
Answer: A - 26.4 uC
Explanation: Use Q = CV. Q = (2.2 x 10^-6 F)(12 V) = 2.64e-05 C = 26.4 uC. The magnitude of charge on each
plate is the same, with opposite signs.
2. A capacitor stores 24 uC when the potential difference across it is 24 V. What is its
capacitance?
A. 2 uF
B. 10 uF
C. 1 uF
D. 500 nF
Answer: C - 1 uF
Explanation: Capacitance is C = Q/V. Thus C = (24 x 10^-6 C)/(24 V) = 1e-06 F = 1 uF.
3. A 20 uF capacitor carries a charge of 240 uC. What is the potential difference across it?
A. 12 V
B. 120 V
C. 24 V
D. 6 V
Answer: A - 12 V
Explanation: From C = Q/V, solve for V = Q/C. Using the same micro-prefix for Q and C, V = 240/20 = 12 V.
4. A capacitor of 4.7 uF is connected across a 24 V source. What charge is stored on either
plate?
A. 113 uC
B. 1.13 mC
C. 56.4 uC
D. 226 uC
Answer: A - 113 uC
Explanation: Use Q = CV. Q = (4.7 x 10^-6 F)(24 V) = 0.000113 C = 113 uC. The magnitude of charge on each
plate is the same, with opposite signs.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 3
, 5. A capacitor stores 18 uC when the potential difference across it is 12 V. What is its
capacitance?
A. 15 uF
B. 750 nF
C. 1.5 uF
D. 3 uF
Answer: C - 1.5 uF
Explanation: Capacitance is C = Q/V. Thus C = (18 x 10^-6 C)/(12 V) = 1.5e-06 F = 1.5 uF.
6. A 5 uF capacitor carries a charge of 45 uC. What is the potential difference across it?
A. 90 V
B. 9 V
C. 18 V
D. 4.5 V
Answer: B - 9 V
Explanation: From C = Q/V, solve for V = Q/C. Using the same micro-prefix for Q and C, V = 45/5 = 9 V.
7. A capacitor of 10 uF is connected across a 15 V source. What charge is stored on either
plate?
A. 150 uC
B. 300 uC
C. 1.5 mC
D. 75 uC
Answer: A - 150 uC
Explanation: Use Q = CV. Q = (10 x 10^-6 F)(15 V) = 0.00015 C = 150 uC. The magnitude of charge on each
plate is the same, with opposite signs.
8. A capacitor stores 36 uC when the potential difference across it is 12 V. What is its
capacitance?
A. 6 uF
B. 30 uF
C. 1.5 uF
D. 3 uF
Answer: D - 3 uF
Explanation: Capacitance is C = Q/V. Thus C = (36 x 10^-6 C)/(12 V) = 3e-06 F = 3 uF.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 4
PHYS 112
GENERAL PHYSICS II
CAPACITANCE & DIELECTRICS
100-QUESTION PRACTICE TEST
Answers, calculations & detailed explanations after every question
100 70+ A-D
QUESTIONS CALCULATIONS FORMAT
Capacitance • Parallel Plates • Dielectrics • Series & Parallel • Energy • Breakdown
, FORMULA REFERENCE
C = Q/V | Q = CV | V = Q/C
Parallel plates: C = k epsilon_0 A/d
Parallel: C_eq = C1 + C2 + ...
Series: 1/C_eq = 1/C1 + 1/C2 + ...
Energy: U = (1/2)CV^2 = Q^2/(2C) = (1/2)QV
Uniform field: E = V/d
Dielectric inserted fully: C = kC0
Battery connected: V constant; Q and U increase with k
Battery disconnected: Q constant; V and U decrease by k
Vacuum permittivity: epsilon_0 = 8.854 x 10^-12 F/m
Coverage: capacitance fundamentals, parallel-plate geometry, dielectric behavior, series/parallel networks, energy storage, electric fields, and
dielectric breakdown.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 2
, 1. A capacitor of 2.2 uF is connected across a 12 V source. What charge is stored on either
plate?
A. 26.4 uC
B. 13.2 uC
C. 264 uC
D. 52.8 uC
Answer: A - 26.4 uC
Explanation: Use Q = CV. Q = (2.2 x 10^-6 F)(12 V) = 2.64e-05 C = 26.4 uC. The magnitude of charge on each
plate is the same, with opposite signs.
2. A capacitor stores 24 uC when the potential difference across it is 24 V. What is its
capacitance?
A. 2 uF
B. 10 uF
C. 1 uF
D. 500 nF
Answer: C - 1 uF
Explanation: Capacitance is C = Q/V. Thus C = (24 x 10^-6 C)/(24 V) = 1e-06 F = 1 uF.
3. A 20 uF capacitor carries a charge of 240 uC. What is the potential difference across it?
A. 12 V
B. 120 V
C. 24 V
D. 6 V
Answer: A - 12 V
Explanation: From C = Q/V, solve for V = Q/C. Using the same micro-prefix for Q and C, V = 240/20 = 12 V.
4. A capacitor of 4.7 uF is connected across a 24 V source. What charge is stored on either
plate?
A. 113 uC
B. 1.13 mC
C. 56.4 uC
D. 226 uC
Answer: A - 113 uC
Explanation: Use Q = CV. Q = (4.7 x 10^-6 F)(24 V) = 0.000113 C = 113 uC. The magnitude of charge on each
plate is the same, with opposite signs.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 3
, 5. A capacitor stores 18 uC when the potential difference across it is 12 V. What is its
capacitance?
A. 15 uF
B. 750 nF
C. 1.5 uF
D. 3 uF
Answer: C - 1.5 uF
Explanation: Capacitance is C = Q/V. Thus C = (18 x 10^-6 C)/(12 V) = 1.5e-06 F = 1.5 uF.
6. A 5 uF capacitor carries a charge of 45 uC. What is the potential difference across it?
A. 90 V
B. 9 V
C. 18 V
D. 4.5 V
Answer: B - 9 V
Explanation: From C = Q/V, solve for V = Q/C. Using the same micro-prefix for Q and C, V = 45/5 = 9 V.
7. A capacitor of 10 uF is connected across a 15 V source. What charge is stored on either
plate?
A. 150 uC
B. 300 uC
C. 1.5 mC
D. 75 uC
Answer: A - 150 uC
Explanation: Use Q = CV. Q = (10 x 10^-6 F)(15 V) = 0.00015 C = 150 uC. The magnitude of charge on each
plate is the same, with opposite signs.
8. A capacitor stores 36 uC when the potential difference across it is 12 V. What is its
capacitance?
A. 6 uF
B. 30 uF
C. 1.5 uF
D. 3 uF
Answer: D - 3 uF
Explanation: Capacitance is C = Q/V. Thus C = (36 x 10^-6 C)/(12 V) = 3e-06 F = 3 uF.
PassPointPro | PHYS 112 - Capacitance & Dielectrics Page 4
