Ohms law involves 3 variables - Voltage (\(E\), for Electromotive force) Resistance (\(R\)), and Current (\(I\)). In a recent webcast, Gordon West suggested a simple method for remembering their order. He suggests that you think of \(E\) as an Eagle, \(I\) as an Igloo, and \(R\) as a Rabbit.

Any time \(E\) is on the left side, \(I\) and \(R\) are on the right side; the Igloo and the Rabbit are both on the ground, so they go next to each other (multiplication, or \(E=I\times R\)). If \(E\) is on the right side, then the Eagle is always on top (in the air). So Resistance is \(\frac{E}{I}\), because the Eagle is always above the Igloo. Current (\(I\)) is \(\frac{E}{R}\), because the eagle is always above the Rabbit. (Remember that \(\frac{E}{R}\) means \(E\) divided by \(R\))

This might help you remember the formulae for Ohms Law.

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Tags: ohm's law electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

Ohms law involves 3 variables - Voltage (\(E\), for Electromotive force) Resistance (\(R\)), and Current (\(I\)). In a recent webcast, Gordon West suggested a simple method for remembering their order. He suggests that you think of \(E\) as an Eagle, \(I\) as an Igloo, and \(R\) as a Rabbit.

Any time \(E\) is on the left side, \(I\) and \(R\) are on the right side; the Igloo and the Rabbit are both on the ground, so they go next to each other (multiplication, or \(E=I\times R\)). If \(E\) is on the right side, then the Eagle is always on top (in the air). So Resistance is \(\frac{E}{I}\), because the Eagle is always above the Igloo. Current (\(I\)) is \(\frac{E}{R}\), because the eagle is always above the Rabbit. (Remember that \(\frac{E}{R}\) means \(E\) divided by \(R\))

This might help you remember the formulae for Ohms Law.

Last edited by kd7bbc. Register to edit

Tags: ohm's law electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

Ohms law involves 3 variables - Voltage (\(E\), for Electromotive force) Resistance (\(R\)), and Current (\(I\)). In a recent webcast, Gordon West suggested a simple method for remembering their order. He suggests that you think of \(E\) as an Eagle, \(I\) as an Igloo, and \(R\) as a Rabbit.

Any time \(E\) is on the left side, \(I\) and \(R\) are on the right side; the Igloo and the Rabbit are both on the ground, so they go next to each other (multiplication, or \(E=I\times R\)). If \(E\) is on the right side, then the Eagle is always on top (in the air). So Resistance is \(\frac{E}{I}\), because the Eagle is always above the Igloo. Current (\(I\)) is \(\frac{E}{R}\), because the eagle is always above the Rabbit. (Remember that \(\frac{E}{R}\) means \(E\) divided by \(R\))

This might help you remember the formulae for Ohms Law.

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Tags: ohm's law resistance electromotive force (voltage) electrical current arrl chapter 3 arrl module 4

Ohms law involves 3 variables - Voltage (\(E\), for Electromotive force) Resistance (\(R\)), and Current (\(I\)). In a recent webcast, Gordon West suggested a simple method for remembering their order. He suggests that you think of \(E\) as an Eagle, \(I\) as an Igloo, and \(R\) as a Rabbit.

Any time \(E\) is on the left side, \(I\) and \(R\) are on the right side; the Igloo and the Rabbit are both on the ground, so they go next to each other (multiplication, or \(E=I\times R\)). If \(E\) is on the right side, then the Eagle is always on top (in the air). So Resistance is \(\frac{E}{I}\), because the Eagle is always above the Igloo. Current (\(I\)) is \(\frac{E}{R}\), because the eagle is always above the Rabbit. (Remember that \(\frac{E}{R}\) means \(E\) divided by \(R\))

This might help you remember the formulae for Ohms Law.

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Tags: math ohm's law resistance electrical current electromotive force (voltage) arrl chapter 3 arrl module 4

\(E = I \times R\)

\(R = \frac{E}{I}\) \(=\) \(\frac{12}{1.5}\) = \(8\) ohms

See Ohm's Law on Wikipedia

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Tags: math ohm's law resistance electromotive force (voltage) electrical current arrl chapter 3 arrl module 4

\(E = I \times R\)

\(R = \frac{E}{I}\) \(=\) \(\frac{12}{4}\) \(=\) \(3\) ohms

See Ohm's Law on Wikipedia

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\(E = I \times R\)

\(I = \frac{E}{R} = \frac{120}{80} = 1.5 \text{ amperes}\)

See Ohm's Law on Wikipedia

• E = Electromotive force (Volts)
• I = Intensity (Amperes)
• R = Resistance (Ohms)

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Tags: math ohm's law electromotive force (voltage) resistance electrical current arrl chapter 3 arrl module 4

Voltage = Current \(\times\) Resistance

Which we can write as: \[E = I \times R\]

Where:

• \(E\) is the voltage applied to the circuit, in volts (V)
• \(I\) is the current flowing in the circuit, in amperes (A)
• \(R\) is the resistance in the circuit, in ohms (\(\Omega\))

In this case we have voltage and resistance and need to find current, so rearrange the equation: \begin{align} E &= I \times R\\ I &= \frac{E}{R}\\ \end{align}

Time to plug and chug! \begin{align} I &= \frac{200 \text{ V}}{100\ \Omega}\\ I &= 2 \text{ A}\\ \end{align}

---

See Ohm's Law on Wikipedia

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Tags: ohm's law electrical current math resistance electromotive force (voltage) arrl chapter 3 arrl module 4

\(E = I \times R\)

\(I = \frac{E}{R} = \frac{240}{24} = 10\) amperes

See Ohm's Law on Wikipedia

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Tags: ohm's law math electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

This is an Ohm's law question. Remember

\(E = I \times R\)

\(E = 0.5 \text{ A} \times 2\ \Omega = 1 \text{ V}\)

See Ohm's Law on Wikipedia

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Tags: ohm's law math electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

Ohm's Law is the relationship between voltage, current, and the resistance in a DC circuit. It can be represented in the equation:

\(E = I \times R\)

Where \(E\) is the voltage/electromotive force (\(E\)), \(I\) is the current (\(A\)), and \(R\) is the resistance (Ω).

If you have any two values in the equation you can find the third:

• \(E = I \times R\)
• \(R = \frac{E}{I}\) (obtained by dividing both sides by I)
• \(I = \frac{E}{R}\) (obtained by dividing both sides by R)

So for our equation:

• \(E = ?\)
• \(I = 1A\)
• \(R = 10Ω\)

\(E = I \times R = 10Ω \times 1A = 10V\)

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Tags: ohm's law math electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

\(E = I \times R = 2 \times 10 = 20\) volts

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Tags: ohm's law math electrical current electromotive force (voltage) resistance arrl chapter 3 arrl module 4

Series is correct. In series current is the same through all components.

In the animation below, the amount of voltage is indicated by the darkness of the green, and the current is represented by the "walking ant" animation.

The voltage is not the same everywhere in this series but the current is!

Easy way to remember the difference between series and parallel, is parallel is like train tracks they run side by side. Series is like a movie series, one episode after another.

Hint: "If Current is the Same in all components" It is Series.

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Tags: arrl chapter 3 arrl module 3

In the animation below, the amount of voltage is indicated by the darkness of the green, and the current is represented by the "walking ant" animation.

Notice the green is the same across all components. There is full source voltage on one side and no voltage on the other, but voltage is the same across all components because they're in parallel.

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Tags: arrl chapter 3 arrl module 3