17.4. The Capacitor http://www.ck12.org
- We have a large charged hollow sphere with a small hole in one side. The charge on the sphere is 1.00 C. We
insert another conducting sphere through the hole on an insulating stick and touch the inside of the charged
hollow sphere and bring the second sphere outside the large sphere. What will be the charge on the second
sphere? - Why does a charged object lose its charge when it is touched to the ground?
- If a charged rubber rod is placed on a wooden table, the rubber rod will keep its charge for a long time. Why
doesn’t the rod lose its charge immediately? - Both a 3. 3 × 10 −^6 Fand a 6. 8 × 10 −^6 Fcapacitor are connected across a 15.0 V potential difference. Which
capacitor has a greater charge and what is that charge?
Review
Questions
- The two plates of a capacitor hold+ 2. 5 × 10 −^3 Cand− 2. 5 × 10 −^3 Cof charge when the potential difference
is 950 V. What is the capacitance? - The potential difference between two parallel wires in air is 120. V. They hold equal and opposite charges of
9. 5 × 10 −^11 C. What is the capacitance of the two wires? - How much charge flows from a 12.0 V battery when it is connected to a 9.00 microfarad capacitor?
- grounding:Making an electrical connection to the earth which results in all charge being removed.
- capacitance:The ability of an object to hold an electrical charge.
- capacitor:A device specifically designed to hold an electrical charge.
- farad:The unit of capacitance in the SI system equal to the capacitance of a capacitor having an equal and
opposite charge of 1 coulomb on each plate and a potential difference of 1 volt between the plates.