Exam 25: Capacitance

An air-filled parallel-plate capacitor has a capacitance of 1 pF. The plate separation is then doubled and a wax dielectric is inserted, completely filling the space between the plates. As a result, the capacitance becomes 2 pF. The dielectric constant of the wax is:

The capacitance of a cylindrical capacitor can be increased by:

Capacitors C₁ and C₂ are connected in series. The equivalent capacitance is given by:

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:

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

To store a total of 0.040 J of energy in the two identical capacitors shown, each should have a capacitance of:

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:

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

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

The units of capacitance are equivalent to:

A capacitor C "has a charge Q". The actual charges on its plates are:

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

Two conducting spheres have radii of R₁ and R₂ with R₁ greater than R₂. If they are far apart the capacitance is proportional to:

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

The plate areas and plate separations of five parallel plate capacitors are Rank these according to their capacitances, least to greatest.

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:

Each of the four capacitors shown is 500 $\mu$ F. The voltmeter reads 1000V. The magnitude of the charge, in coulombs, on each capacitor plate is:

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

A parallel-plate capacitor, with air dielectric, is charged by a battery, after which the battery is disconnected. A slab of glass dielectric is then slowly inserted between the plates. As it is being inserted:

Pulling the plates of an isolated charged capacitor apart: