Module 2 concepts Flashcards
Consider an air-filled charged capacitor. How can it’s capacitance be increased?
Decrease the spacing between the plates of the capacitor.
Consider a charged parallel-plate capacitor. How can its capacitance be halved?
Double the plate separation, and halve the plate area?
Consider a charged parallel plate capacitor. What would quadruple its capacitance?
Halve the plate separation and double the plate area.
If the spacing between the plates, d, is the same in both capacitors, and the voltage across capacitor 1 is V, what is the voltage across capacitor 2? The capacitors are in series.
V/2
If the spacing between the plates in capacitor 1 is d, what should the spacing between the plates in capacitor 2 be to make the capacitance of the two capacitors equal? Capacitor has twice the amount of voltage.
2d
is charged up to a potential V0 with a charge of magnitude Q0 on each plate. It is then disconnected from the battery, and the plates are pulled apart to triply their original separation. What is the new capacitance in terms of C?
C/3
is charged up to a potential V0 with a charge of magnitude Q0 on each plate. It is then disconnected from the battery, and the plates are pulled apart to triply their original separation. How much charge is now on the plates in terms of Q0?
Q0
A parallel-plate capacitor C is charged up to a potential V0 with a charge of magnitude Q0 on each plate. It is then disconnected from the battery, and the plates are pulled apart to triply their original separation. What is the potential difference across the plates in terms of V0?
3V0
The voltage applied across a given parallel-plate capacitor is doubled. How is the energy stored in the capacitor affected?
The energy stored in the capacitor quadruples its original value.
If a dielectric material, such as Teflon®, is placed between the plates of a parallel-plate capacitor without altering the structure of the capacitor, how is the capacitance affected?
The capacitance increases because of the insertion of the Teflon®.
A dielectric material, such as Teflon®, is placed between the plates of a parallel-plate capacitor without altering the structure of the capacitor. The charge on the capacitor is held fixed. How is the voltage across the plates of the capacitor affected?
The voltage decreases because of the insertion of the Teflon®.
If the potential of plate 1 is V, then, in equilibrium, what are the potentials of plates 3 and 6? Assume that the negative terminal of the battery is at zero potential. The capacitors are in parallel.
V and 0
If the charge of the first capacitor (the one with capacitance C ) is Q , then what are the charges of the second and third capacitors? The capacitors are in parallel.
2Q and 3Q
Consider the combination of capacitors shown in the figure. Three capacitors are connected to each other in series, and then to the battery. The values of the capacitances are C, 2C, and 3C, and the applied voltage is ΔV. Initially, all of the capacitors are completely discharged; after the battery is connected, the charge on plate 1 is +Q. What are the charges on plates 3 and 6?
+Q and -Q
Consider the combination of capacitors shown in the figure. Three capacitors are connected to each other in series, and then to the battery. The values of the capacitances are C, 2C, and 3C, and the applied voltage is ΔV. Initially, all of the capacitors are completely discharged; after the battery is connected, the charge on plate 1 is Q. If the voltage across the first capacitor (the one with capacitance C ) is ΔV1 , then what are the voltages across the second and third capacitors?
½ ΔV1 and ⅓ ΔV1
At the same temperature, two wires made of pure copper have different resistances. The same voltage is applied at the ends of each wire. The wires may differ in…
length, cross-sectional area, and the amount of electrical current passing through them
What will be the resistance Rstretched of the copper wire if it is stretched to twice its original length? Assume that the density and resistivity of the material do not change when the wire is stretched.
Express your answer in terms of the wire’s original resistance R.
4R
If all of the dimensions of a block double (to become 20 cm wide, 8 cm tall, and 6 cm deep), what happens to the resistance along each axis?
The resistance is halved.
Immediately after the switch is closed, what is the voltage across the capacitor?
Zero
Immediately after the switch is closed, what is the voltage across the resistor?
E
