Series Circuits
Given: VT = 24 V (the battery)
R1 = 3Ω, R2 = 6 Ω, R3 = 9 Ω
What is the total resistance?
RT = 18 Ω
A toaster pulls a current of 2A, and has a resistance of 60 ohms. What is the voltage drop across the toaster?
120V
A two-branch parallel circuit has a 3V battery, a 6 ohm resistor on the first branch, and a 4 ohm resistor on the second branch. What is the total current in the circuit?
1.25A
Write down all the possible manipulations of the equation for power using the variables P, I and V.
P = I x V V = P / I I = P / V
A voltmeter measure what?
measure potential difference in a circuit
Given: VT = 24 V (the battery)
R1 = 3Ω, R2 = 6 Ω, R3 = 9 Ω
What is I total?
I = 1.33 A
A pencil sharpener draws a current of 3A and is connected to a wall outlet that provides 120V. What is the resistance of the pencil sharpener?
40 ohms
A circuit has three parallel branches. The total current in the circuit is 9A. If each branch has a single 30 ohm resistor on it, how much current goes through each branch?
3A
An iron heats up when plugged into a 120V wall outlet. If the iron has a power rating of 600W, how much current does it pull?
5A
How is a voltmeter connected to a circuit?
in parallel
Current is a series circuit is__________
The same
A 500 ohm appliance and a 300 ohm appliance are both connected (in series) to a 240V outlet. How much current do these appliances draw in total?
0.3A
A two-branch parallel circuit is connected to a 18V power supply, and has a total current of 3A. The current through the first branch is 1.25A. Determine the resistance in the first branch, and the resistance in the second branch.
14.4 ohms in first branch. 10.29 ohms in second branch
A wall oven has a resistance of 2000 ohms, and requires 240V. Calculate the power that the oven runs on.
28.8W
Why is a voltmeter connected in parallel?
parallel branches have the same potential difference
Given: VT = 24 V (the battery)
R1 = 3Ω, R2 = 6 Ω, R3 = 9 Ω
What is the voltage across R1?
V1=4V
A circuit with a 7 ohm and 3 ohm resistor are connected in series to a power supply set to 20V. Calculate the voltage drop across the 7 ohm resistor.
14V
In a parallel circuit with two branches, there is a 100 ohm resistor on the first branch, and two 20 ohm resistors on the second branch. If the current through the first branch is 0.1A, then what is the current through the second branch?
0.25 A
What is the definition of electrical power?
The amount of electrical energy converted in one second.
What do ammeters measure?
current
Draw a circuit with a 9V battery, a switch, 20 ohm resistor and a bulb
Drawings
A circuit with a 4 ohm, a 9 ohm and 5 ohm resistor are connected in series to a power supply set to 9V. Calculate the voltage drop across the 5 ohm resistor.
2.5V
A parallel circuit has three branches. In the first branch, there a 20 ohm resistor. There is a 10 ohm resistor on the second branch and a 5 ohm resistor on the third branch. Calculate the total resistance in the circuit.
2.86 ohms
Two 4 Ω resistors are connected in parallel. This combination is connected in series with a 4 Ω resistor. What is the equivalent resistance of this combination?
6 Ω
What is the Law of Conservation of Charge?
Charge cannot be created or destroyed
current must also be conserved
current flowing into any point = current flowing out