lab letrik.docx

8/10/2019 LAB LETRIK.docx

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introduction

Dalam laporan ini, kami akan menjelaskan setiap perkara yang mungkin berkaitan

dengan perintang asas. Kami ini supaya kita boleh mendapatkan pengetahuan untuk

memperbaiki diri kita dalam hal ini dan berkongsi pengetahuan di kalangan rakan-rakan.

Resistor adalah komponen pasif yang sering digunakan. Perintang tidak mempunyai

kutub. Ia boleh didapati dalam pelbagai bentuk dan saiz. Dua ciri-ciri utama perintang rintangan

(R) dalam ohm dan tahap kuasa dalam watt.

Perintang digunakan untuk membatasi arus dalam litar atau untuk mendapatkan voltan

yang turun merentasinya.

perlawanan adalah rendah, arus yang besar boleh melaluinya. Dua kesan berlaku apabila arus

melalui perintang. Panas yang dihasilkan b. Voltan jatuh


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TITLE

Measurement of resistor value

OBJECTIVES

At the end of this experiment, studentshould be able to

I. Determine the resistance value using colour code table

II. Calculate the tolerance value for given resistor

III. Measure the resistor value using multimeter

EQUIPMENT

I. Analog multimeter and digital multimeter

II. Variable DC power supply

III. Bread board

IV. Resistor

V. Calculator

VI. Wire clips

THEORY

The resistor is a component that limits the flow of current in a circuit. There is a large selection

of resistor depends on its suitability in the circuit. Resistor can be categorized into two type

which are fixed and variable. The value of the fixed resistor is determined by the colour code or

the value printed. Resistor commonly has four bands. Table 1 shows the value of colour band for

a resistor. To calculate and enter the percentage error, we need to use the following formula :

Percentage error = [(nominal valuemeasured value) / nominal value] 100%


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Table 1

Resisitor colour code

Resistor colour code used in small resistor. Resisitor value is found by reading the line on the

resistor colour code. The table shows the resistor colour code table. Most resistors have four

band. The first three lines give the reading of a nominal value of the resistor, while the fourthband indicates the tolerance.


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Factor affecting resistance

The value of resistance is influenced by several factors as follows;

a) The length of the conductor (wire) (L)

Unit of length is meter (m).

The resistance is proportional to the length of conductor.

b) Cross-sectional area of conductor (A)

Unit of Cross-sectional area is in square meters (m2).

The resistance is inversely proportional to the cross-sectional area (A) of conductor R .

Which is the smaller cross-sectional area (A) of conductor, may effect the higher

resistance value.

c) Type of substances/material

or resistivity is representing the nature or type of conducting material.

d) Temperature (T)

R

R

R L

R L


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PROCEDURE :


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DATA AND RESULT :

R1

Resistor Colour BandTolerances

(%) Percentage Error

( % )Band 1 Band 2 Band 3 Band 4

Max.

value

Min.

value

Ungu

7

Hijau

5

Merah

100

Emas

5 %7875 7125

1.3 %

1.2 %

Nominal ValueMeasured Value by

Analog Multimeter

Measured Value by

Digital Multimeter

7500 7400 7410

Ungu Hijau Merah Had terima

7 5 100 = 7500

Jalur had terima ialah emas iaitu 5%

Had terima = 7500 0.05

= 375

Oleh itu, julat nilai rintangan = ( 7500 + 375 ) = 7875

Hingga ( 7500 - 375 ) = 725


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Percentage error by analog multimeter

= [( 7500 - 7400 ) / 7500 ] 100 = 1.33 %

Percentage error by digital multimeter

= [( 7500 - 7410 ) / 7500 ] 100 = 1.2 %

R2


(%) Percentage Error( % )

Band 1 Band 2 Band 3 Band 4Max.

value

Min.

value

Hijau

5

Biru

6

Hitam

1

Emas

5 %58.8 53.2

4.4 %

1.43 %


Analog Multimeter

Measured Value by

Digital Multimeter

56 53.5 55.2

Hijau biru hitam had terima

5 6 1 = 56



= 2.8

Oleh itu, julat nilai rintangan = ( 56 + 2.8 ) = 58.8

Hingga ( 56 - 2.8 ) = 53.2


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= [( 56 - 53.5 ) / 56 ] 100 = 4.46 %


= [( 56 - 55.2 ) / 56 ] 100 = 1.43 %

R3




value

Min.

value

Coklat

1

Hitam

0

Kuning

10k

Emas

5%105 k 95 k

0 %

10 %


Analog Multimeter

Measured Value by

Digital Multimeter

100 k 100 k 90 k

coklat hitam kuning Had terima

1 0 10 k = 100 k


Had terima = 100 k 0.05

= 5 k

Oleh itu, julat nilai rintangan = ( 100 k + 5 k ) = 105k

Hingga ( 100 k - 5 k ) = 95k


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= [( 100 k - 100 k )/ 100 k ] 100 = 0%


= [( 100 k - 90 k ) / 100k ] 100 = 10%

R4




valueMin. value

Oren

3

Hitam

0

Coklat

10

Emas

5 %315 285

- 3.33 %

- 0.3 %


Analog Multimeter

Measured Value by

Digital Multimeter

300 310 301

oren hitam coklat Had terima

3 0 10 = 300



= 15

Oleh itu, julat nilai rintangan = ( 300 + 15 ) = 315

Hingga ( 300 - 15 ) = 285


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= [( 300 - 310 ) / 300 ] 100 = - 3.33 %


= [( 300 - 301 ) / 300 ] 100 = - 0.3 %

R5




value

Min.

value

Kuning

4

Ungu

7

Oren

1k

Emas

5%49 350 44 650

4.6 %

1.9 %

Nominal Value

Measured Value by

Analog Multimeter

Measured Value by

Digital Multimeter

47 000 44 800 46 100

Kuning ungu oren Had terima

4 7 1000 = 47 000


Had terima = 47 000 0.05

= 2350

Oleh itu, julat nilai rintangan = ( 47 000 + 2350 ) = 49350


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Hingga ( 47 000 - 2350 ) = 44650


= [( 47 000 - 44 800 ) / 47 000 ] 100 = 4.6 %


= [( 47 000 - 46 100 ) / 47 000 ] 100 = 1.9 %

R6




Max.

value

Min.

value

Oren

3

Putih

9

Oren

1000

Emas

5%40 950 37 050

2.6 %

1.8 %


Analog Multimeter

Measured Value by

Digital Multimeter

39 000 38 000 38 300

oren putih oren Had terima

3 9 1000 = 39 000


Had terima = 39 000 0.05

= 1950

Oleh itu, julat nilai rintangan = ( 39 000 + 1950 ) = 40 950


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Hingga ( 39 000 - 1950 ) = 37 050


= [( 39 000 - 38 000 ) / 39 000 ] 100 = 2.6 %


= [( 39 000 - 38 300 ) / 39 000 ] 100 = 1.8 %

R7




Max.

value

Min.

value

Merah

2

Merah

2

Hitam

1

Emas

5 %23.1 20.9

1.8 %

0.4 %


Analog Multimeter

Measured Value by

Digital Multimeter

22 22.4 21.9

Merah merah hitam Had terima

2 2 1 = 27



= 1.1



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Hingga ( 22 - 1.1 ) = 20.9


= [( 22 - 22.4 ) / 22 ] 100 = -1.8 %


= [( 22 - 21.9 ) / 22 ] 100 = 0.4%

R8




Max.

value

Min.

value

Kelabu

8

Merah

2

Hitam

1

Emas

5% 86.1 77.9

2.4 %

1.5 %


Analog Multimeter

Measured Value by

Digital Multimeter

82 80 83.3

Kelabu merah hitam Had terima

8 2 1 = 82



= 4.1


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Hingga ( 82 - 4.1 ) = 77.9


= [( 82 - 80 ) / 82 ] 100 = 2.4 %


= [( 82 - 83.3 ) / 82 ] 100 = -1.5 %

R9




Max.

value

Min.

value

Coklat

1

Hitam

0

Kuning

10 000

Emas

5%105 000 95 000

0 %

0.03 %


Analog Multimeter

Measured Value by

Digital Multimeter

100 000 100 000 99 700

Coklat Hitam kuning Had terima

1 0 10 000 = 100 000


Had terima = 100 000 0.05

= 5000


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Oleh itu, julat nilai rintangan = ( 100 000 + 5000 ) = 105 000

Hingga ( 100 000 - 5000 ) = 95 000


= [( 100 000 - 100 000 ) / 100 000 ] 100 = 0 %


= [( 100 000 - 99 700 ) / 100 000 ] 100 = 0.03 %




Max.

value

Min.

value

Oren

3

Biru

6

Merah

100 5 % 3 780 3 420

0 %

0.5 %


Analog Multimeter

Measured Value by

Digital Multimeter

3 600 3 600 3 580

Oren biru Merah Had terima

3 6 100 = 3 600


Had terima = 3 600 0.05

= 180


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Oleh itu, julat nilai rintangan = ( 3 600 + 180 ) = 3780

Hingga ( 3600 - 180 ) = 3420


= [( 3 600 - 3 600 ) / 3 600 ] 100 = 0 %


= [( 3 600 - 3 580 ) / 3 600 ] 100 =0.5 %

DISCUSSION :

1. List four factor when selecting resistor.

I. Determine the resistance

II. Determine the Watts to be dissipated by the Resistor

III. Determine the proper Watt Size (physical size) as controlled by

watts, volts, permissible temperatures, mounting conditions and

circuit conditions.

IV. Choose the most suitable kind of unit, including type, terminals and

mounting.

2. The resistor value for resistor can be determine by the four colour bands. how do you

interpret four color bands.


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3. resistor can be categorized into two type : fixed and variable. Explain it.

a) Fixed resistor

Fixed resistor - the value of a resistor can be obtained from the color code

Tolerance is the relief of actual value. The smaller of tolerance value, the more

accurate reading of the resistor.

Rated poweris the maximum power that can be accepted by the resistance

without incurring damage. If the power is exceeded, the resistor will be damaged

by excessive heat.

Stabilityis the ability of a resistor to maintain the resistance value even the

ambient temperature are change.

b) Variable resistor

Variable resistor is a resistor that can be changed by moving the contact

resistance elements. Variable resistor is used in circuits that require changes in

current and voltage.


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