111Equation Chapter 1 Section 1
BASIC MEASUREMENT OF
ELECTRIC
Devi Putriana, Dewi Adyani, Muh.Haliq Ma’ruf L, Nur Mukarramah, Uswatun
Hasanah
Basic Physics Laboratory Department Of Biology Science Faculty 2013
State University Of Makassar
Abstrak. Has been done made experiment about “Basic Measurement Electric”. This is experiment purpose to investigating relationship between voltage and electric current in a series of simple and the calculate the great obstacles a resistor. In experiment only there is one activity. Procedure work at this experiment that is prepare all tool and material which needful and assemble series electric of simple and than in assemblies voltmeter and amperemeter definited to be at position limite measure highest for avoid damage. Afterwards to flame power ration and pay attention indication voltmeter dan amperemeter. After that move on rheostat at position minimum and than read indication scale voltmeter and amperemeter and write at table observation. After that boosting up voltage source with move on rheostat until volmeter indicating value the highest. From this is experiment we are acquire result that value from resistant can be calculated highest when already it knowed highest from voltage and electric current until connection between voltage with electric current that is comparable.
Key words : Electric Current , Electric Voltage, Resistant, Voltmeter and Amperemeter.
INTRODUCTION
In everyday life we often encounter electricity with a simple electric circuit to form a series of very complicated. Electricity is indeed has become a basic requirement that we cannot release it. Almost all the electronic stuff that we use require electricity in its use. Television, Radio, computer and other electrical needs to be enabled. These items are even included in the electric circuit.
Electric current that flows in a of carriage be either direct current or direct current ( dc ) and be either alternating current ( ac ). Electric current the direction opposite to the direction the flow of electrons, namely an electric current flowing of potential highest to potential lowest, while electrons flowing with otherwise.
George Simon Ohm discover a law of electricity which is called or known as ohm's law the original headquarters consists of several parts. The first part is none other than the definition of obstacles that V = I R, the second part is that this section is not fully known to us on ohmic contact, where R = fixed (Constant Resistor) the equation is known as ohm's law. Ohm also say that R is a constant, which often does not depend on V and I. To that end, practical activities at this time to do an experiment about basic electrical measurements in order to know how the currents and voltages in a circuit and can count a big obstacle on the resistor.
THEORY
In our study of conductor in electrostatic (basic physics), it is argued that the electric field inside a conductor in electrostatic equilibrium conditions must be zero. If not, charge-free charge inside the conductor will move. We now suppose a situation where charges are free indeed move in a conductor. This means that the conductor is not in a State of electrostatic equilibrium. The current in the conductor is produced by an electric charge inside the conductor when the prompt style on a charge-free charge. Because field E in line with the force on a positive charge, and because the direction of the current flow direction is a positive charge, the direction of direct current to the electric field. Picture 3.1 shows a
segment of wire with a length of L And the cross section of latitude a carrying A current of
I
Because the direction of an electric field of the potential potential regional higher to
lower potential at a point greater than point b. Assum that L Small enough we can assume electric field across segments is constant a potential difference V between point a and than b is
V = Va – Vb = EL [5.1]
[image:2.595.211.430.548.608.2]A L
Gambar 3.1. Representasi segmen kawat yang membawa arus I
a E b
for most materials,
“A current in a segments wire proportional to the potential difference across segments” This experimental result is known as Ohm's law. Proportional constants are written 1/R, which R that is resistance:
I
=
1
R
V
atauR
=
V
R
[5.2]The above equation gives a general definition of the resistance between two points of a decrease of voltage V between two points. The SI unit of resistance, volt per ampere, called
ohm () : 1 = 1 V/A.
The resistance of a material depends on the length, cross-sectional area, the type of material, latitude and temperature. For materials that obey Ohm's law is not dependent on flow resistance; material like this, like most metals, is called ohmic materials. For voltage, ohmic material fell on a comparable with the current segment:
V = I R , with R = constan
This equation with the qualification that R constan, gave a mathematical statement of Ohm's law. This law is not the law's fundamental nature such as Newton's laws or laws of thermodynamics but the empirical description of nature is that a lot of the material.
METHODOLOGY EXPERIMENT
At this is experiment we are doing activity measurement basic electric. Before started the activity, more than we are prepare tool and material, that is Power Supplay, Basic Meter, Rheostat, Resistant,and some cable which connects.
After that we are the started up procedure work. At the first that is prepare tool and material which needful and assemble series electric. Before flame ration power, firm assembling voltmeter and Amperemeter be in a placelimit highest for avoid damage. And than flame ration power and pay attention indication voltmeter and amperemeter.after that move on Rheostat at position maximum. If pin tool measue deviate very small, relegating limit measure until indication deviate enough far. Shift return Rheostat at position maximum. Read indication voltmeter dan amperemeter at position mentioned and write at table observation. Boost voltage source with shift Rheostat until voltmeter indicated which more value and read indication amperemeter. Do activity (6) with change linier until acquired a minimum 8 data measure.
Power supply DC is a tool which use as resources electric current in the series electric. And than variable responce is electric current which electric current is the number of electric charge caused of the movement of electrons, flows through a point in electrical circuits each unit time. An electric current can be measured in unit coulomb / second or ampères (A).
RESULT EXPERIMENT AND ANALYSIS DATA
[image:4.595.134.541.283.625.2]Value R = 100 Ω NST Voltmeter = 0,2 V NST Ammeter = 0,002 A
Tabel 5.1 Table connection between Voltage and Electric Current
No. Voltage (V) Electric Current (A)
1
2
3
4
5
6
7
8
|
4,2
±
0,1
|
|
4,4±0,1|
|
4,6
±
0,1
|
|
4,8±0,1|
|
5,0
±
0,1
|
|
5,2±0,1|
|
5,4
±
0,1
|
|
5,6±0,1|
|
0,040
±
0,001
|
|
0,041±0,001|
|
0,043
±
0,001
|
|
0,045±0,001|
|
0,047
±
0,001
|
|
0,049±0,001|
|
0,051
±
0,001
|
0.04 0.05 0.06 0 1 2 3 4 5 6
Electric Current (I)
V o lt a g e ( V )
Chart of relatonship between Voltage and Electric Current
Data Analysis
Tan
θ=
y
x
= R
R =
V
I
=
y
x
R =
V
I
=
∆ V
∆ I
=
5,6
−
4,2
0,053
−
0,040
=
1,4
0,013
= 107,7 Ω
∆ ∆V
=NST ∆V
n
=0,5
2
= 0,25 V∆ ∆ I
=NST ∆ I
n
=0,01
2
= 0,005 I∆ R
=|
∆ ∆ V
∆ V
+
∆ ∆ I
∆ I
|
˟
R=
|
0,25
1,4
+
0,005
0,013
|
107,7˟=
|
0,178
+
0,384
|
107,7˟= 60,52 Ω
DK =
∆ R
R
=˟
100%=
60,52
107,7
˟
100% = 56,19 %= 43,81%
PR = | R ± ∆ R |
PR = | 107,70
±
60,52 | Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
˟
100 %=
|
100
−
107,7
100
|
˟
100 %=
|
7,7
|
%Calculation Analysis
R1 = V1
I1
=
4,2
0,040
= 105 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×100%
100
−
105
100
×
100%
= |5|%
R2 = V2
I2
=
4,4
0,041
= 107,3 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×100%
=
100
−
107,3
100
×
100%
=
|
7,3
|
%R3 = V3
I3
=
4,6
0,043
= 106,9 Ω%Diff =
Rt h eory
−
Rexperiment
=
100
−
107
100
˟
100%=
|
7|
%R4 =
V
4I
4=
4,8
0,045
= 106,6 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×
100%
=
100
−
106,6
100
˟
100%
=
|
6,6|
%R5 =
V
5I
5=
5
0,047
= 106,3 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×
100%
=
100
−
106,3
100
×100%
=
|
6,3|
%R6 =
V
6I
6=
5,2
0,049
= 106,1 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×
100%
=
100
−
106,1
100
100%
=
|
6,1|
%R7 =
V
7I
7=
5,4
%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×
100%
=
100
−
105,8
100
×100%
=
|
5,8|
%R8 =
V
8I
8=
5,8
0,053
= 109,4 Ω%Diff =
Rt h eory
−
Rexperiment
Rt h eory
×
100%
=
100
−
109,4
100
×100%
=
|
9,4|
%DISCUSSION
In an experiment that has been done that is investigating the relationship between voltage and electric current which is measured using a basic meter with the help of the rhesostat slides on the maximum position so it can be retrieved on the designation of the voltmeter and ammeter. On the voltmeter scale used 50 Vsedangkan limit of measurement used is 50 v. on the Ammeter scale used is 100 mA and boundary measure used jga 100 Ma. Wiring should also be matched with the poles on each basicmeter (Ammeter and Voltmeter). To get the data the designation on the voltmeter and ammeter rheostat, then moved. When the rheostat is at a maximum, then the automatic designation on the volmeter ammeter and shifted to the right. mpada experiments conducted, the cables had been attached to a voltmeter and ammeter is connected also with obstacles and when the power supply is turned on and the rheostat shifted, then a voltmeter and ammeter will show the voltage magnitude and powerful arusnya. Shifting is done with interval 1 scale so at basicmeter shows the difference in 1 scale on each data retrieval on the Voltmeter and Ammeter conducted as many as 8 times. The results of observations are shown in basicmeter (Ammeter and Volmeter) is then multiplied by the NST respectively.
to the upside. When great obstacles, then certainly a strong electric current which flows the less/fewer. The barriers also is the quotient between the potential difference between the end-unjungnya with a powerful electric current flowing in the conductor.
CONCLUSSION
In the experiment we are can cocluded that is voltage comparabel with electric current. More biggest voltage, then more biggest as well as electric current which through. Whereas electric current is current which through a conductor comparabel flip over with resistant. More biggest resistant, Whereas more small electric current which through.
REFERENCE
Halliday, David dan Resnick, Robert. 1999. Fisika Jilid 2 Edisi Kelima (Terjemahan). Jakarta: Erlangga.
