Exam 16: Electrical Energy and Capacitance

A pair of parallel plates,forming a capacitor,are connected to a battery.While the capacitor is still connected to the battery maintaining a constant voltage,the plates are pulled apart to triple their original distance.What is the ratio of the final energy stored to the original energy stored?

If two parallel,conducting plates have equal positive charge,the electric field lines will:

If an electron is accelerated from rest through a potential difference of 1,000 V,find its approximate velocity at the end of this process.(e = 1.6 × 10−¹⁹ C;m_e = 9.1 × 10−³¹ kg)

Two equal positive charges are separated by d.Then one of the charges is replaced by a negative charge of the same magnitude.Take the potential at infinity to be zero.In which situation is the potential higher midway between the charges;is this value of potential zero?

Two parallel-plate capacitors have the same plate area,and the gap between the plates is filled with a dielectric with a dielectric constant equal to 8.The gap in capacitor A is one half that in Capacitor B.What is the ratio of the capacitance of A to B?

What is the equivalent capacitance of the combination shown?

There is a hollow,conducting,uncharged sphere with a negative charge inside the sphere.Consider the electrical potential at the inner and outer surfaces of the sphere.Which of the following is true?

Two capacitors with capacitances of 1.0 μF and 0.35 μF,respectively,are connected in parallel.The system is connected to a 40-V battery.What electrical potential energy is stored in the 1.0-μF capacitor?

A free electron is in an electric field.With respect to the field,it experiences a force acting:

If the distance between two negative point charges is increased by a factor of three,the resultant potential energy is what factor times the initial potential energy?

If C₁ = 30 µF,C₂ = 25 µF,C₃ = 15 µF,and ΔV₀ = 22 V,determine the energy stored by C₂.

A 4-μF capacitor is attached to a 10-V power supply.How much energy is stored in the capacitor?

Two protons,each of charge 2.2 × 10^-19 C,are 4.6 × 10^-5 m apart.What is the change in potential energy if they are brought 2.3 × 10^-5 m closer together? (k_e = 8.99 × 10⁹ N·m²/C²)

Two capacitors with capacitances of 1.25 and 3.75 μF,respectively,are connected in parallel.The system is connected to a 45-V battery.What charge accumulates on the 1.25-μF capacitor?

A 20-μF capacitor is attached across a 1000-V power supply.What is the net charge on the capacitor?

A parallel-plate capacitor with plate area A and plate separation d has a capacitance of 3 With the gap between the plates unfilled.The gap is then filled with two dielectric materials,one with dielectric constant 3 and the other one with dielectric constant 6.Each slab of dielectric has area A and thickness d/2,the layering of the dielectrics resulting in the gap being completely filled.Which of the following combinations of capacitors will have the same capacitance as the newly filled parallel-plate one?

A capacitor is made by taking two sheets of aluminum foil,each 0.022 mm thick and placing between them a sheet of paper which comes from a ream of 520 sheets,the ream being 5.3 cm thick with sheets measuring 216 mm by 279 mm (the usual 8 1/2 by 11).What is the capacitance of the capacitor made this way if the dielectric constant of the paper is 3.7? (ε₀ = 8.85 × 10^-12 C²/N × m²)

If the distance between two isolated parallel plates that are oppositely charged is doubled,the electric field between the plates is essentially unchanged.However,the:

A solid conducting sphere of 9 cm radius has a net charge of 17 nC.If the potential at infinity is taken as zero,what is the potential at the center of the sphere?

Three capacitors of 0.6,1.6,and 2.6 μF are connected in series.Find the combined capacitance.