Question 1

What is the difference between a polar dielectric and a nonpolar dielectric?

Accepted Answer

A) A polar dielectric has a permanent electric field. 
B) A nonpolar dielectric never has an internal electric field. 
C) The molecules of a polar dielectric have a permanent electric dipole moment. 
D) A nonpolar dielectric can have an induced electric field in any direction. 
E) A polar dielectric is always aligned with the Earth's electric field. 
A) A polar dielectric has a permanent electric field. 
B) A nonpolar dielectric never has an internal electric field. 
C) The molecules of a polar dielectric have a permanent electric dipole moment. 
D) A nonpolar dielectric can have an induced electric field in any direction. 
E) A polar dielectric is always aligned with the Earth's electric field.

Question 2

Each plate of a capacitor stores a charge of magnitude 1 mC when a 100-V potential difference is applied.The capacitance is:

Accepted Answer

A) 5 $\mu$F 
B) 10 $\mu$F 
C) 50 $\mu$F 
D) 100 $\mu$F 
E) none of these 
A) 5 $\mu$F 
B) 10 $\mu$F 
C) 50 $\mu$F 
D) 100 $\mu$F 
E) none of these

Question 3

The units of capacitance are equivalent to:

Accepted Answer

A) J/C 
B) V/C 
C) J2/C 
D) C/J 
E) C2/J 
A) J/C 
B) V/C 
C) J2/C 
D) C/J 
E) C2/J

Question 4

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 battery and connected to two other capacitors C2 and C3, as shown.The charge on the positive plate 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 *0 10 - -8 C and q3 = 3.0 *10 - 8 C 
B) q2 = 2.0 *10 - 8  C and q3 = 2.0 *10 - 8 C 
C) q2 = 5.0 *10 - 8  C and 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  C and q3 = 3.0 *10 - 8 C 
A) q2 = 3.0 *0 10 - -8 C and q3 = 3.0 *10 - 8 C 
B) q2 = 2.0 *10 - 8  C and q3 = 2.0 *10 - 8 C 
C) q2 = 5.0 *10 - 8  C and 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  C and q3 = 3.0 *10 - 8 C

Question 5

Let Q denote charge, V denote potential difference and U denote stored energy.Of these quantities, capacitors in parallel must have the same:

Accepted Answer

A) Q only 
B) V only 
C) U only 
D) Q and U only 
E) V and U only 
A) Q only 
B) V only 
C) U only 
D) Q and U only 
E) V and U only

Question 6

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) one-fourth the original 
E) quadrupled 
A) doubled 
B) halved 
C) unchanged 
D) one-fourth the original 
E) quadrupled

Question 7

A 2-$\mu$F and a 1-$\mu$F capacitor are connected in series and a potential difference is applied across the combination.The 2-$\mu$F capacitor has:

Accepted Answer

A) twice the charge of the 1-$\mu$F capacitor 
B) half the charge of the 1-$\mu$F capacitor 
C) twice the potential difference of the 1-$\mu$F capacitor 
D) half the potential difference of the 1-$\mu$F capacitor 
E) none of the above 
A) twice the charge of the 1-$\mu$F capacitor 
B) half the charge of the 1-$\mu$F capacitor 
C) twice the potential difference of the 1-$\mu$F capacitor 
D) half the potential difference of the 1-$\mu$F capacitor 
E) none of the above

Question 8

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 9

Capacitors C1 and C2 are connected in series and a potential difference is applied to the combination.If the capacitor that is equivalent to the combination has the same potential difference, then the charge on the equivalent capacitor is the same as:

Accepted Answer

A) the charge on C1 
B) the sum of the charges on C1 and C2 
C) the difference of the charges on C1 and C2 
D) the product of the charges on C1 and C2 
E) none of the above 
A) the charge on C1 
B) the sum of the charges on C1 and C2 
C) the difference of the charges on C1 and C2 
D) the product of the charges on C1 and C2 
E) none of the above

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

An air-filled capacitor is charged, and then a dielectric is inserted.As a result, there is an induced charge on the dielectric.What is the difference between induced charge and free charge?

Accepted Answer

A) There is no difference. 
B) Induced charge does not result in a net charge on the dielectric. 
C) Induced charge is smaller than free charge. 
D) Free charge creates an electric field, but induced charge does not. 
E) Free charge creates an electric potential, but induced charge does not. 
A) There is no difference. 
B) Induced charge does not result in a net charge on the dielectric. 
C) Induced charge is smaller than free charge. 
D) Free charge creates an electric field, but induced charge does not. 
E) Free charge creates an electric potential, but induced charge does not.

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

Two capacitors are identical except that one is filled with air and the other with oil.Both capacitors carry the same charge.The ratio of the electric fields Eair/Eoil is:

Accepted Answer

A) between 0 and 1 
B) 0 
C) 1 
D) between 1 and infinity 
E) infinite 
A) between 0 and 1 
B) 0 
C) 1 
D) between 1 and infinity 
E) infinite

Question 14

A 20-µF capacitor is charged to 200 V.Its stored energy is:

Accepted Answer

A) 4000 J 
B) 4 J 
C) 0.4 J 
D) 0.1 J 
E) 0.004 J 
A) 4000 J 
B) 4 J 
C) 0.4 J 
D) 0.1 J 
E) 0.004 J

Question 15

The capacitance of a parallel-plate capacitor is:

Accepted Answer

A) proportional to the plate area 
B) proportional to the charge stored 
C) independent of any material inserted between the plates 
D) proportional to the potential difference of the plates 
E) proportional to the plate separation 
A) proportional to the plate area 
B) proportional to the charge stored 
C) independent of any material inserted between the plates 
D) proportional to the potential difference of the plates 
E) proportional to the plate separation

Question 16

A parallel-plate capacitor has a plate area of 0.2 m2 and a plate separation of 0.1 mm.To obtain an electric field of 2.0 *106 V/m between the plates, the magnitude of the charge on each plate should be:

Accepted Answer

A) 3.5 * 10-6 C 
B) 7.1 *10-6 C 
C) 1.4 * 10-5 C 
D) 1.8 * 10-5 C 
E) 8.9 * 10-5 C 
A) 3.5 * 10-6 C 
B) 7.1 *10-6 C 
C) 1.4 * 10-5 C 
D) 1.8 * 10-5 C 
E) 8.9 * 10-5 C

Question 17

If the plate area 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 18

A 2-$\mu$F and a 1-$\mu$F capacitor are connected in series and charged from a battery.They store charges P and Q, respectively.When disconnected and charged separately using the same battery, they have charges R and S, respectively.Then:

Accepted Answer

A) R > S > Q = P 
B) P > Q > R = S 
C) R > P = Q > S 
D) R = P > S = Q 
E) R > P > S = Q 
A) R > S > Q = P 
B) P > Q > R = S 
C) R > P = Q > S 
D) R = P > S = Q 
E) R > P > S = Q

Question 19

A charged capacitor stores 10 C at 40 V.Its stored energy is:

Accepted Answer

A) 400 J 
B) 200 J 
C) 4 J 
D) 2.5 J 
E) 1.25 J 
A) 400 J 
B) 200 J 
C) 4 J 
D) 2.5 J 
E) 1.25 J

Exam 25: Capacitance

What is the difference between a polar dielectric and a nonpolar dielectric?

Each plate of a capacitor stores a charge of magnitude 1 mC when a 100-V potential difference is applied.The capacitance is:

The units of capacitance are equivalent to:

Let Q denote charge, V denote potential difference and U denote stored energy.Of these quantities, capacitors in parallel must have the same:

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

A 2- μ\muμ F and a 1- μ\muμ F capacitor are connected in series and a potential difference is applied across the combination.The 2- μ\muμ F capacitor has:

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:

Capacitors C1 and C2 are connected in series and a potential difference is applied to the combination.If the capacitor that is equivalent to the combination has the same potential difference, then the charge on the equivalent capacitor is the same as:

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:

An air-filled capacitor is charged, and then a dielectric is inserted.As a result, there is an induced charge on the dielectric.What is the difference between induced charge and free charge?

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

Two capacitors are identical except that one is filled with air and the other with oil.Both capacitors carry the same charge.The ratio of the electric fields Eair/Eoil is:

A 20-µF capacitor is charged to 200 V.Its stored energy is:

The capacitance of a parallel-plate capacitor is:

A parallel-plate capacitor has a plate area of 0.2 m2 and a plate separation of 0.1 mm.To obtain an electric field of 2.0 *106 V/m between the plates, the magnitude of the charge on each plate should be:

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

A 2- μ\muμ F and a 1- μ\muμ F capacitor are connected in series and charged from a battery.They store charges P and Q, respectively.When disconnected and charged separately using the same battery, they have charges R and S, respectively.Then:

A charged capacitor stores 10 C at 40 V.Its stored energy is:

Measurement

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Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

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The Kinetic Theory of Gases

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Filters

A 2- $\mu$ F and a 1- $\mu$ F capacitor are connected in series and a potential difference is applied across the combination.The 2- $\mu$ F capacitor has:

Capacitors C₁ and C₂ are connected in series and a potential difference is applied to the combination.If the capacitor that is equivalent to the combination has the same potential difference, then the charge on the equivalent capacitor is the same as:

Two capacitors are identical except that one is filled with air and the other with oil.Both capacitors carry the same charge.The ratio of the electric fields E_air/E_oil is:

A parallel-plate capacitor has a plate area of 0.2 m² and a plate separation of 0.1 mm.To obtain an electric field of 2.0 *10⁶ V/m between the plates, the magnitude of the charge on each plate should be:

A 2- $\mu$ F and a 1- $\mu$ F capacitor are connected in series and charged from a battery.They store charges P and Q, respectively.When disconnected and charged separately using the same battery, they have charges R and S, respectively.Then: