Electricity: Ohm's Law
Electricity involves the flow of charged particles (electrons) through a conductor. Ohm's Law describes the relationship between voltage, current, and resistance in an electrical circuit: V = I x R.
What You Need to Know
Key Concept Diagram
Current (I): the flow of electric charge, measured in amperes (A)
Voltage (V): the "push" that drives current around a circuit, measured in volts (V)
Resistance (R): the opposition to current flow, measured in ohms (omega)
Ohm's Law: V = I x R (Voltage = Current x Resistance)
Series circuits: components connected in a single loop; parallel circuits: components on separate branches
Key Vocabulary
Current
The rate of flow of electric charge, measured in amperes (A)
Voltage
The electrical potential difference (energy per unit charge) that drives current, measured in volts (V)
Resistance
A material's opposition to the flow of electric current, measured in ohms
Ohm's Law
The relationship V = IR: voltage equals current multiplied by resistance
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
A circuit has a resistance of 10 ohms and a current of 2 A. What is the voltage?
Question 2
A 12 V battery is connected to a 6 ohm resistor. What is the current?
Question 3
In a series circuit with two identical bulbs, if one bulb is removed, what happens to the other?
Key Concepts Summary
- ●Current (I): the flow of electric charge, measured in amperes (A)
- ●Voltage (V): the "push" that drives current around a circuit, measured in volts (V)
- ●Resistance (R): the opposition to current flow, measured in ohms (omega)
- ●Ohm's Law: V = I x R (Voltage = Current x Resistance)
- ●Series circuits: components connected in a single loop; parallel circuits: components on separate branches