Question 1

The quantity (1/2)$\varepsilon$0E2 has the significance of:

Accepted Answer

A)  energy/farad 
B)  energy/coulomb 
C)  energy 
D)  energy/volume 
E)  energy/volt 
A)  energy/farad 
B)  energy/coulomb 
C)  energy 
D)  energy/volume 
E)  energy/volt

Question 2

A certain capacitor has a capacitance of 5.0 $\mu$F. After it is charged to 5 $\mu$C and isolated, the plates are brought closer together so its capacitance becomes 10 $\mu$F. The work done by the agent is about:

Accepted Answer

A)  0 
B)  1.25 *10-6 J 
C)  -1.25 * 10-6 J 
D)  8.3* 10-7 J 
E)  -8.3 * 10-7 J 
A)  0 
B)  1.25 *10-6 J 
C)  -1.25 * 10-6 J 
D)  8.3* 10-7 J 
E)  -8.3 * 10-7 J

Question 3

Two parallel-plate capacitors with different capacitance but the same plate separation are connected in series to a battery. Both capacitors are filled with air. The quantity that is the same for both capacitors when they are fully charged is:

Accepted Answer

A)  potential difference 
B)  stored energy 
C)  energy density 
D)  electric field between the plates 
E)  charge on the positive plate 
A)  potential difference 
B)  stored energy 
C)  energy density 
D)  electric field between the plates 
E)  charge on the positive plate

Question 4

A parallel-plate capacitor has a plate area of 0.2 m2 and a plate separation of 0.1 mm. If the charge on each plate has a magnitude of 4 *10-6 C the potential difference across the plates is approximately:

Accepted Answer

A)  0 
B)  4 *10-2 V 
C)  1 *102 V 
D)  2 *102 V 
E)  4 * 108 V 
A)  0 
B)  4 *10-2 V 
C)  1 *102 V 
D)  2 *102 V 
E)  4 * 108 V

Question 5

The capacitance of a spherical capacitor with inner radius a and outer radius b is proportional to:

Accepted Answer

A)  a/b 
B)  b - a 
C)  b2 - a2 
D)  ab/(b - a) 
E)  ab/(b2 - a2) 
A)  a/b 
B)  b - a 
C)  b2 - a2 
D)  ab/(b - a) 
E)  ab/(b2 - a2)

Question 6

The capacitance of a single isolated spherical conductor with radius R is proportional to:

Accepted Answer

A)  R 
B)  R2 
C)  1/R 
D)  1/R2 
E)  none of these 
A)  R 
B)  R2 
C)  1/R 
D)  1/R2 
E)  none of these

Question 7

If both the plate area and the plate separation of a parallel-plate capacitor are doubled, the capacitance is:

Accepted Answer

A)  doubled 
B)  halved 
C)  unchanged 
D)  tripled 
E)  quadrupled 
A)  doubled 
B)  halved 
C)  unchanged 
D)  tripled 
E)  quadrupled

Question 8

If the charge on a parallel-plate capacitor is doubled:

Accepted Answer

A)  the capacitance is halved 
B)  the capacitance is doubled 
C)  the electric field is halved 
D)  the electric field is doubled 
E)  the surface charge density is not changed on either plate 
A)  the capacitance is halved 
B)  the capacitance is doubled 
C)  the electric field is halved 
D)  the electric field is doubled 
E)  the surface charge density is not changed on either plate

Question 9

Capacitors A and B are identical. Capacitor A is charged so it stores 4 J of energy and capacitor B is uncharged. The capacitors are then connected in parallel. The total stored energy in the capacitors is now:

Accepted Answer

A)  16 J 
B)  8 J 
C)  4 J 
D)  2 J 
E)  1 J 
A)  16 J 
B)  8 J 
C)  4 J 
D)  2 J 
E)  1 J

Question 10

Two parallel-plate capacitors with different plate separation but the same capacitance are connected in series to a battery. Both capacitors are filled with air. The quantity that is NOT the same for both capacitors when they are fully charged is:

Accepted Answer

A)  potential difference 
B)  stored energy 
C)  electric field between the plates 
D)  charge on the positive plate 
E)  dielectric constant 
A)  potential difference 
B)  stored energy 
C)  electric field between the plates 
D)  charge on the positive plate 
E)  dielectric constant

Question 11

Capacitor C1 and C2 are connected in parallel. The equivalent capacitance is given by:

Accepted Answer

A)  C1C2/(C1 + C2) 
B)  (C1 + C2)/C1C2 
C)  1/(C1 + C2) 
D)  C1/C2 
E)  C1 + C2 
A)  C1C2/(C1 + C2) 
B)  (C1 + C2)/C1C2 
C)  1/(C1 + C2) 
D)  C1/C2 
E)  C1 + C2

Question 12

If the plate separation of an isolated charged parallel-plate capacitor is doubled:

Accepted Answer

A)  the electric field is doubled 
B)  the potential difference is halved 
C)  the charge on each plate is halved 
D)  the surface charge density on each plate is doubled 
E)  none of the above 
A)  the electric field is doubled 
B)  the potential difference is halved 
C)  the charge on each plate is halved 
D)  the surface charge density on each plate is doubled 
E)  none of the above

Question 13

Capacitor C1 is connected alone to a battery and charged until the magnitude of the charge on each plate is 4.0 * 10-8 C. Then it is removed from the vattery and connected to two other capacitors C2 and C3, as shown. The charge ont he positive placte of C1 is then 1.0 * 10 - 8 C. The charges on the positive plates of C2 and C3 are:

Accepted Answer

A)  q2 = 3.0 *10 - -8 C and q3 = 3.0 * 10 - 8 C 
B)  q2 = 2.0 *10 - 8  Cand q3 = 2.0 *10 - 8 C 
C)  q2 = 5.0 *10 1- 8  Cand q3 = 1.0 *10  - 8 C 
D)  q2 = 3.0 *10 - 8 C and q3 = 1.0 *10 - 8 C 
E)  q2 = 1.0 * 10 - 8  Cand q3 = 3.0 *10 - 8 C 
A)  q2 = 3.0 *10 - -8 C and q3 = 3.0 * 10 - 8 C 
B)  q2 = 2.0 *10 - 8  Cand q3 = 2.0 *10 - 8 C 
C)  q2 = 5.0 *10 1- 8  Cand q3 = 1.0 *10  - 8 C 
D)  q2 = 3.0 *10 - 8 C and q3 = 1.0 *10 - 8 C 
E)  q2 = 1.0 * 10 - 8  Cand q3 = 3.0 *10 - 8 C

Question 14

The capacitance of a parallel-plate capacitor with plate area A and plate separation d is given by:

Accepted Answer

A)  $\varepsilon$0d/A 
B) $\varepsilon$0d/2A 
C) $\varepsilon$0A/d 
D)  $\varepsilon$0A/2d 
E)  $\varepsilon$d/$\varepsilon$0 
A)  $\varepsilon$0d/A 
B) $\varepsilon$0d/2A 
C) $\varepsilon$0A/d 
D)  $\varepsilon$0A/2d 
E)  $\varepsilon$d/$\varepsilon$0

Question 15

To charge a 1-F capacitor with 2 C requires a potential difference of:

Accepted Answer

A)  2 V 
B)  0.2 V 
C)  5 V 
D)  0.5 V 
E)  none of these 
A)  2 V 
B)  0.2 V 
C)  5 V 
D)  0.5 V 
E)  none of these

Exam 25: Capacitance

The quantity (1/2) ε\varepsilonε 0E2 has the significance of:

A certain capacitor has a capacitance of 5.0 μ\muμ F. After it is charged to 5 μ\muμ C and isolated, the plates are brought closer together so its capacitance becomes 10 μ\muμ F. The work done by the agent is about:

Two parallel-plate capacitors with different capacitance but the same plate separation are connected in series to a battery. Both capacitors are filled with air. The quantity that is the same for both capacitors when they are fully charged is:

A parallel-plate capacitor has a plate area of 0.2 m2 and a plate separation of 0.1 mm. If the charge on each plate has a magnitude of 4 *10-6 C the potential difference across the plates is approximately:

The capacitance of a spherical capacitor with inner radius a and outer radius b is proportional to:

The capacitance of a single isolated spherical conductor with radius R is proportional to:

If both the plate area and the plate separation of a parallel-plate capacitor are doubled, the capacitance is:

If the charge on a parallel-plate capacitor is doubled:

Capacitors A and B are identical. Capacitor A is charged so it stores 4 J of energy and capacitor B is uncharged. The capacitors are then connected in parallel. The total stored energy in the capacitors is now:

Two parallel-plate capacitors with different plate separation but the same capacitance are connected in series to a battery. Both capacitors are filled with air. The quantity that is NOT the same for both capacitors when they are fully charged is:

Capacitor C1 and C2 are connected in parallel. The equivalent capacitance is given by:

If the plate separation of an isolated charged parallel-plate capacitor is doubled:

The capacitance of a parallel-plate capacitor with plate area A and plate separation d is given by:

To charge a 1-F capacitor with 2 C requires a potential difference of:

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Filters

The quantity (1/2) $\varepsilon$ ₀E² has the significance of:

A certain capacitor has a capacitance of 5.0 $\mu$ F. After it is charged to 5 $\mu$ C and isolated, the plates are brought closer together so its capacitance becomes 10 $\mu$ F. The work done by the agent is about:

A parallel-plate capacitor has a plate area of 0.2 m² and a plate separation of 0.1 mm. If the charge on each plate has a magnitude of 4 *10^-⁶ C the potential difference across the plates is approximately:

Capacitor C₁ and C₂ are connected in parallel. The equivalent capacitance is given by: