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⚡️Multimeters - Measuring Voltage
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0:00
So, we're going to check the
0:04
voltage. I'm going to use these two
0:05
jumper wires here.
0:08
And I'm going to place the orange one at
0:10
the positive end, black one at the
0:13
negative end. And what we could do is
0:17
I'm going to go ahead and turn the
0:18
switch on. And we see the blue LED turns
0:20
on. I'm going to place it on the orange
0:23
lead because that's gonna this orange
0:25
lead is on our positive end. And I'm
0:28
going to attach attach the black lead of
0:31
the multimeter to the black jumper wire
0:35
going to ground or the negative of our
0:38
power supply. So now since I'm using a
0:41
9volt battery, I need to use
0:45
a reading on the voltmeter that's higher
0:48
than 9 volts. So the closest value on
0:52
this multimeter to 9 volts that's higher
0:56
than 9 volts is 20 volts. So, I'm going
0:58
to turn the knob from off to 20 volts.
1:02
And right now, I got a reading of 9.08
1:05
volts or 9. Yeah, 9.08 volts. The
1:10
reading across the power supply here on
1:15
the circuit. Now, I'm going to remove
1:17
the jumpers from the jumpers of the
1:21
multimeter from these two jumper wires.
1:25
And I want to see how much a voltage
1:27
drop is across this blue LED. And on the
1:30
cathode of the LED, I'm placing the
1:34
black lead from the multimeter, and I'm
1:37
getting a reading of 2.74 volts. So, I'm
1:40
going to turn my calculator on, and I'm
1:42
going to type in 2.74.
1:45
Now, I'm going to release these and I'm
1:48
going to measure the voltage across the
1:49
resistor now. And right now I'm getting
1:51
a reading of 6.32 volts or 6 6.32 volts.
1:55
So I'm going to press plus 6.32 volts.
2:00
And I'm going to hit enter. And I get
2:02
9.06 volts.
2:05
That was about how much I originally
2:07
read.
2:09
So if I put these back on to the leads
2:12
here, I get 9.07
2:15
volts or 9 almost 9.06
2:18
volt. what I'm getting in our
2:19
calculation here.
2:21
A series circuit acts as a voltage
2:24
divider. So the only thing that we have
2:26
in our circuit here is an LED and a
2:28
resistor. All of the voltage is being
2:30
dropped across the LED and the resistor.
2:33
So part of it was across the LED which
2:36
we measured to be 2.74 volts and part of
2:40
the voltage drop was across the resistor
2:44
which was 6.32 volts is what we
2:46
measured. And if we add those two
2:49
together, the two voltage drops,
2:52
we get 9.06 06 volts which is the
2:55
voltage reading across the power supply
2:59
itself.
#Electrical Test & Measurement