Current and Voltage
Resistance
RC circuits
100
What is Kirchoff's current law?
The sum of all currents at a junction equal zero
100
What is the equation for finding equivalent resistance in a series circuit?
Req = R1 + R2 + R3 .....
100
What is the formula for the time constant T?
T = RC
200
What is Kirchoff's voltage law?
The voltages in a closed loop must add up to zero
200
What is the equation for finding equivalent resistance in a parallel circuit?
1/Req = 1/R1 + 1/R2 + 1/R3 .....
200
What are the units for the time constant?
Seconds
300
The battery in the following figure is short-circuited by an ideal ammeter having zero resistance. Assume that ΔV=4.5V. What is the battery's internal resistance? 
2 Ohms
300
If R1 = R2, what is the potential difference across R2?
7.5 V
300
The current vs time graph for a discharging capacitor _______ decreases
exponentially
400
In the figure, what is the magnitude of the current in the wire to the right of the junction? 
1 A
400
The voltage across the terminals of a 9.0V battery is 8.3V when the battery is connected to a 60 Ohm load.
What is the battery's internal resistance?
5.22 Ohms
400
What is the time constant for the discharge of the capacitors in the figure(Figure 1)? 
2 ms
500
In the following figure, what is the value of the potential at points a and b? 
9V, 1V
500
Compared to an ideal battery, by what percentage does the battery's internal resistance reduce the potential difference across the 20 Ω resistor in the figure?
3.2 %
500
A capacitor is discharged through a 70.0 Ω resistor. The discharge current decreases to 29.0% of its initial value in 1.70 ms. What is the value of the capacitor?
19.6 μF