Question

With the battery voltage set to 20 volts, measure the current in a parallel circuit with 1, 2, 3, and 4 light bulbs. (In each case, place the ammeter next to the battery.) Use Ohm’s law to calculate the total resistance of the circuit. Record results below.
Number of light bulbs
1
2
3
4
Voltage
20 volts
20 volts
20 volts
20 volts
Current
1.33 A
1.33 Amps
0.44 Amps
0.27 Amps
Total resistance(show all work)

Answer 1

Number of light bulbs: 1
Total current: 1.33 A

Total resistance = Voltage / Total current
Total resistance = 20 volts / 1.33 A
Total resistance = 15.04 ohms

Number of light bulbs: 2
Total current: 1.33 A

Total resistance = Voltage / Total current
Total resistance = 20 volts / 1.33 A
Total resistance = 15.04 ohms

Number of light bulbs: 3
Total current: 0.44 A

Total resistance = Voltage / Total current
Total resistance = 20 volts / 0.44 A
Total resistance = 45.45 ohms

Number of light bulbs: 4
Total current: 0.27 A

Total resistance = Voltage / Total current
Total resistance = 20 volts / 0.27 A
Total resistance = 74.07 ohms