Capacitors
Inductors
RC Circuits
RL Circuits
100
True or False: Capacitance is the ability to store electrical charge
TRUE
100
Four 10 mH inductors are in series. The total inductance is __________
40 mH
100
The switch has been closed for a very long time.
What is the charge on the capacitor at t =0s
Q=VC -> 80uC
100
If you want a characteristic RL time constant of 1.00 s, and you have a 500 Ω resistor, what value of self-inductance is needed?
500H
200
Four 22 microfarad capacitors are in parallel. The total capacitance is __________
88 microfarad
200
An ohmmeter (which measures resistance) is connected across an inductor and the pointer indicates an infinite value. The inductor is __________
Open
200
The switch has been closed for a very long time.
The switch is opened at t=0s. At what time has the charge on the capacitor decreased to 10% of its initial value?
.23ms
ln(.10)= -t/(50)(2.0uf)
200
A large superconducting magnet, used for magnetic resonance imaging, has a 50.0 H inductance. If you want current through it to be adjustable with a 1.00 s characteristic time constant, what is the minimum resistance of system?
50 ohms
300
An uncharged capacitor and a resistor are connected in series with a switch and a 12-V battery. At the instant the switch is closed, the voltage across the capacitor is __________
0 Volts
300
DAILY DOUBLE!
Five inductors are connected in series. The lowest value is 5 microHenries. If the value of each inductor is twice that of the preceding one, and if the inductors are connected in order of ascending values, what is the total inductance?
155 microHenries
300
What value resistor will discharge a 1.0uF capacitor to 10% of its initial charge in 2.0 ms?
870 ohms
.1= e-t/rc
solve r
300
What percentage of the final current I0 flows through an inductor L in series with a resistor R, three time constants after the circuit is completed?
95
400
Of air or water, which type of capacitor has the highest dielectric constant?
Water
400
You have a 12 mH inductor and it is your smallest value. You need an inductance of 8 mH. What value can you use in parallel with the 12 mH to obtain 8 mH?
24 mH
400
A 150uF defibrillator capacitor is charged to 1500 V. When fired through a patient’s chest, it loses 95% of its charge in 40 ms. What is the resistance of the patient’s chest?
89 ohms
.05= e-t/rc
solve r
400
how much time is required to bring the current through an 80.0 mH inductor in series with a 15.0 Ω resistor to 99.0% of its final value
24.6 ms
500
Determine the time constant for this series RC combination: R = 100 ohms, C = 1F
100s
500
Determine the time constant for this series RL combination: R = 100 ohms, L = 100 micro Henries
1 micro second
500
A capacitor is discharged through a 100-ohm resistor. The discharge current decreases to 25% of its initial value in 2.5 ms. What is the value of the capacitor?
C = 18uF
500
What are the units of RC and L/R?
s