Download electric circuits 2 and 3

Name: ______________________________ Period: ____
Electric Circuits 2
1. What is resistance?
2. The more resistance a circuit has, the less ________.
3. What is the unit used to measure resistance called? How is it abbreviated?
4. When measuring resistance of an object, does it need to be in the circuit or out of the circuit?
5. Write the formula for Ohm’s Law and label what each abbreviation stand for.
I
V
R
6. A laptop computer runs on a 24-volt battery. If the resistance of the circuit inside is 16 ohms, how much
current does it use?
7. A motor in a toy car needs 2 amps of current to work properly. If the car runs on four 1.5-volt batteries,
what is the motor’s resistance?
8. What is the difference between a conductor, an insulator, and a semiconductor? Which do you think has a
higher resistance?
9. When can insulators be useful?
10. How does a potentiometer use resistance to control the current in a circuit?
Electric Circuits 3
1. A television runs on 120 volts and has a resistance of 60 ohms. What current does it draw?
2. A television remote control uses a current of 0.04 Amps when the power button is pressed. The resistance
inside the remote is 75 Ω. What battery voltage is needed to make the remote work?
3. A hair dryer draws a current of 10 A when plugged into a 120 V outlet. What is the resistance of the hair dryer?
4. For the problems below, use Ohm’s Law to solve for the missing value in each circuit.
5. How many volts would 5 batteries have together (batteries that we use in lab)?
6. How many batteries would it take to reach 97.5 V?
7. a. What happens to a circuit’s current if the resistance increases?
b. What happens to a circuit’s current if the voltage increases?
8. What is the difference between conductors and insulators in terms of
a. amount of current they allow to pass through them?
b. amount of resistance?
c. the types of materials they are made of?
9. A circuit contains a battery, a switch, a resistor and a light bulb (in that order), and a wire completes the
circuit between the light bulb and the battery. Draw a circuit diagram for this circuit.
10. Draw a circuit diagram for the circuit that contains a battery, a light bulb, a second battery, and a switch.
11. Current always flows from the _______ end of a battery to the _______ end.
12. Convert the following:
a. 20 mA to A
b. 330 kΩ to Ω
c. 0.00178 kV to mV