# Ohm's Law

Ohm's law defines a linear relationship between the voltage and the current in an electrical circuit.

The resistor's voltage drop and resistance set the DC current flow through the resistor.

With water flow analogy we can imagine the electric current as water current through pipe, the resistor as a thin pipe that limits the water flow, the voltage as height difference of the water that enables the water flow.

## Ohm's Law Formula / Equation

When we know the voltage and resistance, we can calculate the current.

#### Ohm's law definition

The resistor's current I in amps (A) is equal to the resistor's voltage VR=V in volts (V) divided by the resistance R in ohms (Ω):

V is the voltage drop of the resistor, measured in Volts (V). In some cases Ohm's law uses the letter E to represent voltage. E denotes electromotive force.

I is the electrical current flowing through the resistor, measured in  Amperes (A)

R is the resistance of the resistor, measured in Ohms (Ω)

#### Voltage calculation

When we know the current and resistance, we can calculate the voltage.

The voltage V in volts (V) is equal to the to the current I in amps (A) times the resistance R in ohms (Ω):

#### Resistance calculation

When we know the voltage and the current, we can calculate the resistance.

The resistance R in ohms (Ω) is equal to the voltage V in volts (V) divided by the current I in amps (A):

Since the current is set by the values of the voltage and resistance, the Ohm's law formula can show that:

• If we increase the voltage, the current will increase.
• If we increase the resistance, the current will reduce.

#### Example #1

Find the current of an electrical circuit that has resistance of 50 Ohms and voltage supply of 5 Volts.

Solution:

V = 5V

R = 50Ω

I = V / R = 5V / 50Ω = 0.1A = 100mA

#### Example #2

Find the resistance of an electrical circuit that has voltage supply of 10 Volts and current of 5mA.

Solution:

V = 10V

I = 5mA = 0.005A

R = V / I = 10V / 0.005A = 2000Ω = 2kΩ

## Ohm's Law for AC Circuit

The load's current I in amps (A) is equal to the load's voltage VZ=V in volts (V) divided by the impedance Z in ohms (Ω):

V is the voltage drop on the load, measured in Volts (V)

I is the electrical current, measured in Amps (A)

Z is the impedance of the load, measured in Ohms (Ω)

#### Example #3

Find the current of an AC circuit, that has voltage supply of 110V∟70° and load of 0.5kΩ∟20°.

Solution:

V = 110V∟70°

Z = 0.5kΩ∟20° = 500Ω∟20°

I = V / Z = 110V∟70° / 500Ω∟20° = (110V / 500Ω) ∟ (70°-20°) = 0.22A ∟50°

### Ohm's Law Calculator (short form)

Ohm's law calculator: calculates the relation between Voltage, Current and Resistance.

Enter 2 values to get the third value and press the Calculatebutton:

 Enter Resistance: R = ohms (Ω) Enter Current: I = amps (A) Enter Voltage: V = volts (V)

Ohm's law calculator II ►
The text passage provides an explanation of Ohm's Law, including its formula and how to calculate voltage, current, and resistance. It also includes three examples with solutions that demonstrate the application of Ohm's Law in both DC and AC circuits.
multiple_questions_with_answers
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
# Ohm's Law

Ohm's law defines a linear relationship between the voltage and the current in an electrical circuit.

The resistor's voltage drop and resistance set the DC current flow through the resistor.

With water flow analogy we can imagine the electric current as water current through pipe, the resistor as a thin pipe that limits the water flow, the voltage as height difference of the water that enables the water flow.

## Ohm's Law Formula / Equation

When we know the voltage and resistance, we can calculate the current.

#### Ohm's law definition

The resistor's current I in amps (A) is equal to the resistor's voltage VR=V in volts (V) divided by the resistance R in ohms (Ω):

V is the voltage drop of the resistor, measured in Volts (V). In some cases Ohm's law uses the letter E to represent voltage. E denotes electromotive force.

I is the electrical current flowing through the resistor, measured in  Amperes (A)

R is the resistance of the resistor, measured in Ohms (Ω)

#### Voltage calculation

When we know the current and resistance, we can calculate the voltage.

The voltage V in volts (V) is equal to the to the current I in amps (A) times the resistance R in ohms (Ω):

#### Resistance calculation

When we know the voltage and the current, we can calculate the resistance.

The resistance R in ohms (Ω) is equal to the voltage V in volts (V) divided by the current I in amps (A):

Since the current is set by the values of the voltage and resistance, the Ohm's law formula can show that:

• If we increase the voltage, the current will increase.
• If we increase the resistance, the current will reduce.

#### Example #1

Find the current of an electrical circuit that has resistance of 50 Ohms and voltage supply of 5 Volts.

Solution:

V = 5V

R = 50Ω

I = V / R = 5V / 50Ω = 0.1A = 100mA

#### Example #2

Find the resistance of an electrical circuit that has voltage supply of 10 Volts and current of 5mA.

Solution:

V = 10V

I = 5mA = 0.005A

R = V / I = 10V / 0.005A = 2000Ω = 2kΩ

## Ohm's Law for AC Circuit

The load's current I in amps (A) is equal to the load's voltage VZ=V in volts (V) divided by the impedance Z in ohms (Ω):

V is the voltage drop on the load, measured in Volts (V)

I is the electrical current, measured in Amps (A)

Z is the impedance of the load, measured in Ohms (Ω)

#### Example #3

Find the current of an AC circuit, that has voltage supply of 110V∟70° and load of 0.5kΩ∟20°.

Solution:

V = 110V∟70°

Z = 0.5kΩ∟20° = 500Ω∟20°

I = V / Z = 110V∟70° / 500Ω∟20° = (110V / 500Ω) ∟ (70°-20°) = 0.22A ∟50°

### Ohm's Law Calculator (short form)

Ohm's law calculator: calculates the relation between Voltage, Current and Resistance.

Enter 2 values to get the third value and press the Calculatebutton:

 Enter Resistance: R = ohms (Ω) Enter Current: I = amps (A) Enter Voltage: V = volts (V)

Ohm's law calculator II ►
user
The text passage provides an explanation of Ohm's Law, including its formula and how to calculate voltage, current, and resistance. It also includes three examples with solutions that demonstrate the application of Ohm's Law in both DC and AC circuits.

TYPE: MULTIPLE_QUESTIONS_WITH_ANSWERS