Hello and welcome.
Today we discuss arms law the most symmetrical relationship E equals I multiple by R.
We must at first doing do the math.
Then we will see cash flow a way to predict Turkish behavior.
It all adds up nothing is lost.
Let's first discuss arms law.
Okay.
As you can see here and arms law.
There is a mathematical relationship between the three components of electricity.
That relationship is arms low E for Volts are for assistance in arms are for currents in arms the mathematical
relationship is E equals I multiple by R we can transform it so R equals E divided by i or i equals
E divided by R
in the following sequence of slides we would be doing exercises where we will set up a circuit using
resistors and voltage sources 9 volt battery predict current using arms low and verify our calculation
by using Volt or meter.
This is the circle of arms low E R E equals I multiply by R R equals E divided by R and R equals E divided
by.
This is a simple way to normalize the low.
Now let's look at this circuit.
This is the basic circuit that you will use for the following exercises.
The volt meter will be moved to measure voltage resistance and current.
As you can see here this is here for current and it's placed here for resolving fault or the stores
uh you must hook up this circuit and you'll ball so that you can keep up with the coming slides while
the circuit using 100 on resistor without power applied.
Measure the resistance of that is a store.
Connect the nine volt battery and measure the Volt across.
There is a store called your data.
Now let's see using the voltage and resistance that ohms law.
Calculate the anticipated current.
In this example all equals divided by our example that result in a current of boiling 09 arms or 90
billion amps with avoided it by 8 volt by ninety eight point one ohms These are the practical readings
using the Volt o meter.
The result is 90 million.
Now listen sir the Volt o meter and the circuit as indicated in this diagram it must be in series or
the current flow through it.
As you can see here using the appropriate current range measure the actual current in the circuit.
How does the current compare to your predicting using Ohm's Law.
You need to compare the two results.
There won't be.
There will be a slightly different value.
Uh but one uh be that different since uh Ohm's Law is the same as measuring the Volt on meter but there
is some practical uh some practical let's say not that we must take into consideration such as heat
dissipation and cup of loss.
Now let's see the second exercise.
Select one kilo on resistor and calculate the restricted circuit retained for this exercise that you
do not know what the voltage of the battery is.
Measure that assistance with the bow arm were removed and then the current with Bohr and recall all
of that.
So here we don't know the voltage source.
We measure the current and we measure that as a store and using another configuration forms low.
We can get E equals ie multiple by are using the current.
Understand that alarms low.
Let's calculate anticipated voltage.
It will equal nine point seventy three Volt.
This from the practical measurement using the Volt or meter.
Now let's connect the Volt o meter in the circuit as indicated here using the appropriate Walgreens
measure the actual voltage across the resistor here.
How does the current compare to your prediction using Ohm's Law.
It will uh be really uh clause.
It will equalize both 7 Volt and that case.
Um.
Uh.
We measured.
Uh here now when several walls and the image of the value is lined both three vaults which are really
close to each other.
These are quick exercises to give you a thorough understanding of arms low.
Now let's look at this failed exercise this exercise you'll use an unknown with so the first one the
current wasn't known.
The second one the voltage wasn't known.
Now the current that is this store isn't known.
So we need to calculate it using Ohm's Law.
We must first measure the current and then measure the voltage then using Ohm's Law R equals E divided
by I will give us the current that will give us.
Sorry that is the store value which will be three point three thousand eight hundred forty four ohm
or three point a two K low on.
So it's really close to the real value.
The previous three exact exercises we managed to use Ohm's law to get the current value.
The voltage value and the resistance value in each case two of the three components must be known for
that.
So that we can calculate the fair component that is missing.
Now let's look at arm's law and practice
the next series of slides or exercises will both arms low to use to illustrate some principle of basic
electronics as in the previous exercises you will build the circuit and insert the Volt or meter into
the circuit in the appropriate way to make current and voltage measurement throughout the exercises
record your data so that you can compare it to calculations now.
Let's build this circuit these other resistor values series Battle series and the three are Conference
series together.
And here we have a meta.
Now if we look at the circuit and plays first let's measure the current flowing through the circuit
using this meta then move the Volt or meter to the other side of the circuit and measure the current
here.
The current should be the same as the previous measurement since the graph for a flowing through here
is the same that going back here now and said the Volt o meter at the indicated location and measure
of the current year there should be no surprise that the current is the same
four point six five billion arms.
If you are doing this annual bread board this is the reading of the meta Dow measure the voltage across
our line here using OMS low calculate the voltage drop across along on the store are the current EU
measures.
Here we can calculate the voltage drop if we image of the voltage here using the current and that is
a store we can calculate the voltage so using Oslo equals ie multiple by r e e will equal four point
sixty five volt as you can see here the value is for Boyne
okay four point six five vol.
This is the calculated value and the voltage on the test bed using the volt meter was four point six.
There is no 6 5.
So this is a very small difference between the two circuits.
Now in the next step you will insert the Volt o meter in the circuit at two places illustrated at 1
and 2 here until you record your current readings for both places at the current and compare and contrast
to the current child entering the total circuit.
So if we add these two columns there must equal the main current or the main source of column
now using the current meter throw number one and the resistance value of r to one get along calculate
the voltage drawbacks or accrual across that resistor.
Likewise do the same with the current method.
Throw number 2 and the resistance value of our 3 2 point to create a long compare and contrast these
two values of voltage values uh as you can see in number 1.
Uh the value will be three point two one vote.
And number two the value will be three point 1 6 8 vote.
The value are essentially the same and they should be.
Since the voltage is the same in battle as you can see the voters here must be equal.
The voltage here measure the voltage across the battery with the store and record your answer.
Compare and contrast the voltage measure to the voltage drop calculated the measure of the value will
be three point one seven and that is bad and you can see that there is a very small difference but they
are basically the same values.
Now uh if we looked at this example this said the Volt o meter into the circuit here let's compare and
contrast the results.
It will measure four point six million arms and if we did measure the volunteer uh using the current
you just miss out under the results of our four calculate what the voltage drop across our force would
be to equal one point five to volt listen sell the Volt o meter into the circuit as alleged rated and
measure the voltage.
This is the practical value to compare and contrast the middle damage out and calculated voltage it
will equal one point five six.
They are basically the same.
Um this is one final measurement to complete this portion of the exercise and the Volt o meter indicated
here because the three voltages Mitchell previously across are 1 2 3 and 4.
Add these three voltage together and then compare and contrast the result with the total vultures just
measured.
So throw out one was four point six R1 3 it was three point one 7 while an order for it was one point
five six.
The total output voltage was three boring.
Or nine point three three.
So what you observed was the sum of the individual counts was equal to the total current flowing through
the circuit.
The sum of the voltage drops was equal to the total voltage across the circuit.
This is cash flow and is very useful in the study of electronic circuit.
You also note noted that Ohm's Law applied throughout the circuit.
Uh that's it for Ohm's Law.
I know that I did it really quick but I will applaud that slide so that you can grow each of these exercise
one by one and apply them in your test bed.
This is basically a really simple laundry list but you need to understand it correctly.
Thanks for watching.
And next we will explain to our stores this is education engineering team.