Conceptual Physics

Chapter 26 Problems

Conceptual Problems

C.1 If you increase the potential difference
between the plates of a capacitor, what
happens to (a) the amount of charge on each
plate and (b) the net charge of the capacitor?

(a) i. It increases

ii. It decreases

iii. It stays the same

(b) i. It increases

ii. It decreases

iii. It stays the same

C.2 A dielectric is inserted between the plates of an isolated, charged capacitor, replacing the vacuum that was there before. Its

dielectric constant is greater than one. (a) Has the capacitance increased, decreased, or stayed the same? (b) Is there more,

less, or the same amount of charge on the capacitor?

(a) i. Increased

ii. Decreased

iii. Stayed the same

(b) i. More charge

ii. Less charge

iii. Same amount of charge

Section Problems

Section 0 - Introduction

0.1 Use the simulation in the interactive problem in this section to determine whether the charge on a capacitor is proportional to
the potential difference.
i. Charge is proportional to potential difference
ii. Charge is not proportional to potential difference

Section 1 - Capacitors

1.1

Suppose you disassemble a cell phone and remove a capacitor inside labeled " 6.5eí11 F." If you apply a potential difference

of 5.0 volts across the capacitor, how much charge would you expect to be on the positive plate?

C

1.2 When a 9.0 V battery is connected to a capacitor, it puts 6.0eí4 C of charge on the capacitor. When a different battery with

an unknown voltage is connected to the same capacitor, it puts 1.5×10í^4 C of charge on the capacitor. What is the unknown

battery's voltage?

V

1.3 A capacitor accumulates 6.4eí5 C of charge when connected to a 9.0 volt battery. What is its capacitance?

F

1.4 A 6.1eí6 F capacitor accumulates 51 μC of charge when connected to a battery. What is the battery's voltage?

V

1.5 When a battery is connected to a 2.0 microfarad capacitor, it places an equal but opposite charge on each plate, of
magnitude 4.0×10í^5 coulombs. How much would the same battery charge a 3.6eí6 farad capacitor?
C

Section 4 - Energy in capacitors

4.1 In an electronic circuit, you need a capacitor to store 4.50eí9 J of energy. You have 1.50 volts available to charge it with.

What capacitance should you choose?

F

4.2 Suppose a capacitor in a video camera has a capacitance of 26.0 μF, and is currently holding 5.20eí5 C of charge. How

Copyright 2007 Kinetic Books Co. Chapter 26 Problems^487