Download Series and Parallel Circuits

Series and Parallel Circuits
Name ____________________________________
R1
Block______________ Date______
R2
R3
Total
R2
R3
Total
R2
R3
Total
Current
Voltage
Resistance
VT = 20V
R1
Current
Voltage
Resistance
VT = 12 V
R1
Current
Voltage
Resistance
VT= 12V
Relationships:
1. What happens to current if resistance is decreased?
2. What happens to current if voltage is decreased?
3. What happens to resistance if wire diameter is decreased?
4. What happens to resistance if wire length is decreased?
5. What happens to power if current is decreased (but voltage is constant)?
6. What happens to power if voltage is decreased (but current is constant)?
Draw the following circuits:
1. Two 3 V batteries, two 5 Ohm lamps, and one closed switch in parallel:
2. Two 3 V batteries, two 5 Ohm lamps, and one closed switch in series:
Word Problems:
1. Three resistors are connected in parallel to a battery of 18V, with resistances of 3 ohms, 6 ohms, and 9
ohms, what is the equivalent resistance?
Determine the current in each resistor? What is the total current in the circuit?
2. Four resistors are connected in series to a battery of 6 V, with resistances of 2 ohms, 4 ohms, 5 ohms,
and 7 ohms. What is the equivalent resistance?
What is the voltage drop in each of resistor? What is the current in the circuit?
3. A 620 W toaster operates on a household circuit of 120 V. What is the resistance in the toaster?
4. A 24 V battery is hooked up in series to a 250 ohm resistor and a 150 ohm resistor, what is the
equivalent resistance of the circuit?