Prática de Shadowing: Basic Ohm's Law For Electricians - Aprenda a falar inglês com vídeo

Escolha um modo de prática

Cada modo abre uma sala de prática em tela cheia.

168 frases

Se as frases estiverem muito curtas ou longas, clique em Edit para ajustá-las.

So you need to learn Ohm's Law, but you're lost or have no idea where to start.

Don't panic, you've come to the right place.

In this video, we're going to simplify Ohm's Law for electricians.

Look at a demonstration and finally put the tires to the pavement and do some real calculations using what we've learned.

We'll cover series, parallel, and combination circuits in future installments.

Hey, my name is Dustin.

I'm a licensed master electrician.

I'm also a test prep and apprenticeship instructor.

Welcome to this episode of Smarter Sparky.

So what exactly is Ohm's Law?

To answer that question we have to acknowledge a problem with electricity.

We can't see it, we can't hear it, smell it, taste it or feel it.

Sure we can see lightning, we can hear thunder, and we can get zapped by electricity, right?

But those are all the observable effects from electricity, not the electricity itself.

So the problem with electricity is that it's very difficult to observe, but we can measure it.

The things that we can measure are voltage, current, and resistance.

These are the key players in the battle that is Ohm's law.

Let's take a look at the lineup.

Voltage is kind of like pressure.

Think of low pressure like low voltage and high pressure like high voltage.

It's how much force or more technically electromotive force, which is the technical definition of voltage, is available.

Voltage is symbolized by the letter E.

I know that's kind of weird.

Why isn't it the letter V, right?

It's because we use the letter V as our units, volts.

So that leaves us needing a different letter to symbolize the unknown value.

Therefore we use the letter E from electromotive force.

So for example E equals 12 volts.

Current is similar to flow rate or gallons per hour.

A garden hose is a relatively low gallons per minute so we could think of that as low current.

Whereas a river is moving lots of gallons per minute it would be thought of as a higher current.

Current is symbolized by the letter I for similar reasons as voltage right we need that different letter.

Current is measured in amperes or amps

so we use the letter A for the units

and symbolize it with the letter I which stands for intensity so for example I equals 4 amps.

Resistance is the final contender which can be thought of as a restriction in a water line.

The harder you squeeze a hose, the more the flow is restricted.

Resistance is measured in ohms.

It's symbolized by the letter R, which stands for resistance, and the value is symbolized by the uppercase omega symbol.

For example, R equals 8 ohms.

Resistance is all around us.

All wires have a natural resistance to them.

Bad connections act like a resistance, and we have to treat them as such.

We even have a component called a resistor that is an on-purpose resistance that can be added to a circuit.

Ohm's law is what relates all three of these items together.

Ohm's law states that voltage is equal to current times resistance.

This gives us the first formula, E equals I times R.

We can rearrange this formula and derive two additional formulas giving us a total of three Ohm's law formulas.

Here's the deal.

We don't have to memorize all three.

We can just remember the first one, E equals I times R.

By filling in this triangle, we can cover up the value that we want to solve for and get the resulting formula.

For example, we can cover up E, which leaves it next to IR.

When the leftover values are next to each other, that signifies multiplication.

So E equals I times R, the formula that we started with.

If we want to solve for current, we can simply cover up I, which leaves E over R.

That gives us I equals E divided by R, the second of our formulas.

Finally, we can solve for resistance by covering up R, which leaves E over I.

That gives us R equals E divided by I.

This trick is great for remembering Ohm's Law as you only need to memorize one formula.

You can simplify the triangle just by drawing a T bracket and filling in the values.

That's exactly what I did when I sat down to take my state exam.

Draw the little letter T and fill those values in.

then you've got that Ohm's law formula right there on your scratch paper.

I'm sure you guys have all seen this little cartoon before, something very similar.

It's a great graphical representation of how Ohm's law works.

Voltage or pressure is trying to push current or amps through a wire, pipe, but resistance is restricting how much can actually move.

Let's visualize this concept using the water pipe analogy we've been using.

Here we've got an aquarium pump and a length of tubing.

This hose clamp is going to act as our resistance.

With the clamp fully open and the pump running, we have our maximum current flow.

As the clamp is tightened down, increasing resistance, we can see the current flow decreases.

We get less water or current making it through the pipe.

Let's do a few practical Ohm's Law calculations, one for each of the three Ohm's Law equations.

Consider this circuit.

How much current would flow if we had a resistance of 6 ohms and a voltage of 12 volts?

So it looks like we need to solve for I which is our placeholder for current.

So let's grab our triangle and cover up the letter I and that leaves us with E over R, meaning I equals E divided by R.

Now it's just a matter of plugging the values in.

I equals 12 volts divided by 6 ohms.

12 divided by 6 is 2 amps.

See?

Easy peasy.

What about this circuit?

Now we know the voltage and current, but we don't know the resistance.

Let's grab our triangle and cover up the letter R.

That leaves us with E over I, meaning R equals E divided by I.

Simply plug our values from the diagram into the formula, which gives us R equals 24 volts divided by 6 amps, and we get a resistance of 4 ohms.

Finally, we have this example.

Now we know the current and the resistance, but we don't know what the applied voltage is.

Grabbing our triangle, we can cover up the letter E.

Remember E is voltage which gives us I right next to R meaning E equals I times R.

Plugging in our values we get E equals 5 amps times 8 ohms

and that calculates out to E our voltage equaling 40 volts.

Hey real quick getting noticed by the YouTube algorithm is nearly impossible these days without help from viewers like you.

If you like this teaching style and find this video helpful, please take a second to like and drop a comment.

It lets the algorithmic overlords know this content's worth sharing.

All right, back to the good stuff.

We've just talked about the three items that can be measured for Ohm's Law, voltage, current, and resistance.

100

There's actually a fourth item as well, and that's power.

101

Power is a unit of energy.

102

We symbolize it using the letter P, and it's measured in watts.

103

We use W as the units, watts.

104

Basically power is the rate at which electrical work is performed.

105

For example, a 60 watt light bulb does less work than a 100 watt light bulb.

106

It puts out less light, less heat.

107

The 100 watt light bulb puts out more light and more heat.

108

There is another formula that concerns Watts law.

109

Watts law states that power equals current times voltage or amps times volts.

110

This formula is easy to remember because the variables spell out pi.

111

Check it out.

112

P equals I times E.

113

Everybody likes pi, so it's easy to remember.

114

Let's grab one of our previous examples.

115

We calculated this first example to find out that the current was 2 amps.

116

We can further calculate the power of this circuit by taking the current and multiplying it by the voltage.

117

So the wattage of the load is going to be P equals 2 amps times 12 volts, or 24 watts.

118

Just like Ohm's law, Watt's law has three different arrangements for the same formula.

119

And just like Ohm's law, Watt's law can be put into a triangle to help us remember all of these formulas.

120

Just remember pi and use that to fill in the triangle.

121

Maybe you've seen a wheel like this before.

122

Whether you have or not, it certainly looks intimidating.

123

This wheel is called Ohm's wheel or Watt's wheel and it's actually pretty simple.

124

The way the wheel works is we have four quadrants.

125

Each quadrant calculates out one of the four items we can calculate.

126

Voltage, current, resistance, and power.

127

Each of the quadrants has three formulas within it.

128

So taking E, voltage for example, E equals I times R, E equals P divided by I,

129

and E also equals the square root of P times R.

130

And it works that way for the other quadrants as well.

131

Pretty neat, huh?

132

This wheel actually has Ohm's law built within it.

133

Here's E equals I times R, like we just saw.

134

Here's I equals E divided by R, and here's R equals E divided by I.

135

Watt's law is also in there.

136

Here's pi, P equals I times E, and here's the other two formulas as well.

137

Here's I equals P divided by E, and E equals P divided by I.

138

So that leaves us with six remaining formulas.

139

Where do those come from?

140

These are derived formulas.

141

Basically, they're an algebraic mashup of both Ohm's law and Watt's law.

142

I'll show you one real quick example of where they come from, but don't worry about knowing this.

143

It's only for the curious.

144

For our example, let's take this formula here.

145

E equals the square root of p times r.

146

It's derived by taking the two formulas, i equals p divided by e, and i equals e divided by r.

147

i is equal to i, therefore p divided by e has to be equal to e divided by r.

148

If we cross multiply, we get e squared equals p times r.

149

Take the square root of both sides to undo the square on the e, and we get e equals the square root of p times r.

150

All the other formulas are calculated using the same algebraic concept.

151

It combines Ohm's law and Watt's law to eliminate one of the variables.

152

Make sure to watch the upcoming Ohm's law videos on series, parallel, and combination circuits,

153

and I'm going to show you a way to solve them without actually really even needing these derived formulas.

154

Links will be down in the description when they become available.

155

Ohm's law doesn't have to be confusing.

156

In a simple circuit there's only one voltage, one current, one resistance, and one power.

157

When we get into series, parallel, and combination circuits we will have multiples of each value

158

but I'll show you how to handle that when we get to that point.

159

Just remember we really only need to memorize two formulas.

160

E equals I times R and pi.

161

P equals I times E.

162

Then we can use triangles to solve for anything we need.

163

If you want more practice with basic Ohm's Law, I have a free worksheet and answer key you can download.

164

Links are down in the description.

165

That wraps up basic Ohm's Law.

166

Don't forget to feed the algorithm with all the things the algorithm praise.

167

Like, comment, and a subscription if I have earned it.

168

See you on the next one.

Baixar aplicativo

Tudo o que você precisa para falar fluentemente

Pronúncia com IANota em cada frase

Prática de IPADomine cada som

VocabulárioMonte seu banco de palavras

Jogo de vocabulárioAprenda brincando

Escaneie o QR

Download on theApp Store Get it onGoogle Play

FOR YOU

Vídeo recomendado

82 frases

The Difference Between Contactors And Relays - ELECTROMAGNETIC SWITCHES electricians use

Business EnglishWorking Adults

Vocabulário e dicas de fala para esta lição

Este vídeo tem 168 frases e 1967 palavras para praticar shadowing. A fala dura 11:24. O falante fala em ritmo natural, cerca de 173 palavras por minuto, próximo de uma conversa do dia a dia. Apenas 73% das palavras estão entre as 3.000 mais comuns do inglês, por isso o vocabulário é exigente.

Vocabulário principal deste vídeo

15 palavras do vídeo que vale a pena aprender, com pronúncia e significado:

Palavra	Pronúncia	Significado
formula substantivo	/ˈfɔː.mjʊ.lə/	fórmula
voltage substantivo	/ˈvəʊltɪd͡ʒ/	tensão, voltagem
divide verbo	/dɪˈvaɪd/	dividir, separar
litter substantivo	/ˈlɪt.ɚ/	lixo
circuit substantivo	/ˈsɝ.kɪt/	circuito, volta
triangle substantivo	/ˈtɹaɪˌæŋɡəl/	triângulo
watt substantivo	/wɑt/	watt
leaf substantivo	/lif/	folha
solve verbo	/sɒlv/	resolver, solucionar
calculate verbo	/ˈkælkjʊleɪt/	calcular
electricity substantivo	/ɪˌlɛkˈtɹɪsɪti/	eletricidade
derive verbo	/dɪˈɹaɪv/	derivar
parallel adjetivo	/ˈpæ.ɹəˌlɛl/	paralelo
pipe substantivo	/ˈpaɪp/	flauta
plug substantivo	/plʌɡ/	plugue

Phrasal verbs que você vai ouvir

Palavra	Significado
cover up verbo	encobrir
put out verbo	colocar/botar/pôr para fora
find out verbo	descobrir
wrap up verbo	embrulhar, empacotar

Gramática neste vídeo

As estruturas que o falante mais usa, com as palavras exatas do vídeo:

Estrutura	No vídeo
Voz passiva be + particípio passado — o foco está no que acontece, não em quem faz	is symbolized · would be thought · is measured
Present perfect have/has + particípio passado — uma ação passada que ainda importa agora	you've come · we've learned · We've just talked
Orações relativas who / which + oração — informação extra sobre uma pessoa ou coisa	force, which is · contender which can

Pronúncia para ficar de olho

O falante usa 27 contrações e formas reduzidas, como don't, I'm, we've. Diga-as na forma curta, do jeito que você ouve.

Os sons de “th”: algorithm /ˈælɡəɹɪðm̩/, thunder /ˈθʌndɚ/, algorithmic /ˌælɡəˈɹɪðmɪk/
Os sons de “sh” e “zh”: calculation /ˌkælkjuˈleɪʃn̩/, representation /ˌɹɛp.ɹə.zɛnˈteɪ.ʃən/, examination /ɪɡˌzæm.ɪˈneɪ.ʃən/, demonstration /dɛmənˈstɹeɪʃən/, subscription /səbˈskɹɪpʃən/
Palavras longas — acerte a sílaba tônica: electricity /ɪˌlɛkˈtɹɪsɪti/, electrical /ɪˈlɛktɹɪkəl/, representation /ˌɹɛp.ɹə.zɛnˈteɪ.ʃən/, examination /ɪɡˌzæm.ɪˈneɪ.ʃən/, eliminate /ɪˈlɪm.ɪ.neɪt/

Como praticar com este vídeo

Ouça o vídeo inteiro uma vez sem falar e anote as palavras que você não conhece.
Comece na velocidade 0,75×, faça shadowing frase por frase e volte à velocidade normal quando ficar fácil.
Grave a sua voz e compare com o original, prestando atenção a palavras como formula, voltage, divide.

O que é a Técnica de Shadowing?

Shadowing é uma técnica de aprendizado de idiomas com base científica, originalmente desenvolvida para o treinamento de intérpretes profissionais. O método é simples, mas poderoso: você ouve áudio em inglês nativo e repete imediatamente em voz alta — como uma sombra seguindo o falante com 1-2 segundos de atraso. Pesquisas mostram melhora significativa na precisão da pronúncia, entonação, ritmo, sons conectados, compreensão auditiva e fluência na fala.

Técnica de shadowing: leia o guia completo passo a passo →

Prática de Shadowing: Basic Ohm's Law For Electricians - Aprenda a falar inglês com vídeo

Escolha um modo de prática

Baixar aplicativo

Electrical Terms Explained For English Beginners

avoiding taxes is easy, actually

The Art of Learning Like a Genius (even if you're not one)

Basic Opt Flw regimes

Cursed Units 2: Curseder Units

Functional-Oriented Documentation in Automation - Eplan & IEC 81346 Explained

What does an Architect Do?

My Tesla Powered Boat Gets MAJOR Upgrades

Siemens S7-1200: Signal Modules - Wire, Program, Test

Tricks to Strip Insulated Bond Wire (METAL BOXES)

How Does Electricity Flow Through a Utility-Scale Solar Site?