Practice applying Ohm's law and basic circuit ideas to calculate voltage, current, resistance, and power in simple electric circuits.
Read each problem carefully. Show your work and include units in every answer.
Using voltage, current, and resistance in simple circuits
Physics - Grade 9-12
- 1
A resistor has a resistance of 6 ohms and a current of 2 amperes flows through it. Find the voltage across the resistor.
- 2
A 24 volt battery is connected to a resistor. The current in the circuit is 3 amperes. Find the resistance.
- 3
A circuit has a resistance of 15 ohms and a voltage of 45 volts. Find the current.
- 4
A lamp draws 0.5 amperes from a 120 volt source. What is the lamp's resistance?
- 5
A device has a resistance of 10 ohms and is connected to a 9 volt battery. Find the current in the device.
- 6
Two resistors of 4 ohms and 6 ohms are connected in series. Find the total resistance.
- 7
Two resistors of 12 ohms and 18 ohms are connected in parallel. Find the equivalent resistance.
- 8
A 20 volt source is connected to a series circuit containing a 3 ohm resistor and a 7 ohm resistor. Find the total current in the circuit.
- 9
A 12 volt battery is connected to two parallel resistors of 6 ohms and 3 ohms. Find the equivalent resistance of the circuit.
- 10
A resistor has 18 volts across it and carries 3 amperes of current. How much power does it use?
- 11
An electric heater uses 1200 watts when connected to a 120 volt outlet. Find the current drawn by the heater.
- 12
A phone charger delivers 5 volts and 2 amperes. Find its power output.
- 13
A student says that increasing resistance in a circuit with the same voltage will increase the current. Explain whether this statement is correct.
- 14
Describe the difference between a series circuit and a parallel circuit in terms of current and voltage.
- 15
A 9 volt battery is connected to a resistor and the current is measured as 0.3 amperes. If the battery voltage stays the same and the resistance is doubled, what will the new current be?