bab iii. jembatan wheatstone(1).pdf

LAPORANPRAKTIKUM FISIKA DASAR II

JUDUL PERCOBAANJEMBATAN WHEATSTONE

OLEH :

N A M A :

N I M :

JURUSAN :HARI / TANGGAL :

KELOMPOK :

ASISTEN :

LABORATORIUM FISIKA DASARFAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM

UNIVERSITAS SRIWIJAYA2013 / 2014

Lembar Kerja Praktikum Fisika Dasar II TA. 2013/2014 III-1

III. JEMBATAN WHEATSTONE

3.1. TUJUAN PERCOBAAN1. Mengukur besar hambatan, kapasitas dan membuktikan hukum hubungan seri dan

parallel.

2. Menentukan hambatan jenis suatu kawat penghantar.

3.2 ALAT DAN BAHAN1. Kawat geser (L).

......................................................................................................................................

2. Hambatan, kapasitor dan kawat penghantar.......................................................................................................................................

3. Galvanometer (G).......................................................................................................................................

4. Catu daya arus searah.......................................................................................................................................

..


RR

3

3.3. DASAR TEORI

Jembatan Wheatstone adalah rangkaian yang terdiri atas empat buah hambatanseperti terlihat pada Gambar 1. berikut:

Gambar 1. Skema Jembatan Wheatstone

R1, R2 dan R3 merupakan hambatan-hambatan yang sudah diketahui harganya, sedangkanRx besar hambatan yang akan dicari. Pada keadaan galvanometer (G) menunjukkanangka nol, berlaku hubungan:

Rx R1

32

..................................................... (1)

Jika Rx diganti dengan Cx dan R3 diganti dengan C3, maka diperoleh hubungan:

Cx R1 CR2

..................................................... (2)

Dalam percobaan, harga R1 dan R2 sebanding dengan l1 dan l2 (lihat Gambar 2),sedangkan R3 dan C3 diganti dengan hambatan standard RS dan kapasitor standard CS,

sehingga persamaan (1) menjadi:

Rx l1 Rsl

..................................................... (1)2

Sedangkan persamaan (2) menjadi:

Cx l1 Csl

..................................................... (2)2

Untuk menentukan hambatan jenis suatu kawat penghantar, digunakan persamaan:

R LA

..................................................... (5)

dengan :


R = hambatan kawatL = Panjang kawatA = Luas penampang kawat

= Hambatan jenis kawat

Gambar 2. Rangkaian Jembatan Wheatstone


2.4. PROSEDUR PERCOBAANA. Mengukur Besar Hambatan.

1. Susunlah rangkaian percobaan seperti Gambar 2.2. Atur kontak geser K sehingga galvanometer menunjukkan angka nol.3. Catat panjang l1 dan l2.4. Ganti Rx dengan Ry dan lakukan langkah 2. dan 3. Ulangi untuk Rx dan Ry yang

dihubungkan secara seri dan paralel.5. Lakukan masing-masing minimal 3 kali.

B. Menentukan Hambatan Jenis Kawat Penghantar.1. Dari Gambar 2, ganti Rx dengan kawat penghantar.2. Catat panjang dan diameter kawat penghantar.3. Lakukan seperti prosedur kerja A.2. dan A.3. untuk panjang kawat yang berbeda-

beda. (Sekurang-kurangnya 3 panjang kawat).


3.5. TUGAS PENDAHULUAN1. Jelaskan cara lain untuk mengukur hambatan.2. Buktikan persamaan (1), (2), (3) dan (4).3. a. Apakah syarat agar R1 dan R2 sebanding dengan I1 dan I2.

b. Bagaimana pengaruh pengukuran jika kawat geser tidak homogen.4. Apakah satuan hambatan jenis (satuan SI).

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................


a. DATA HASIL PENGAMATANA. Mengukur Besar Hambatan (RX)

No.E

(volt)RS

(Ohm)l1 (cm) l2 (cm)

1 2 3 4 5 1 2 3 4 5

1.

2.

3.

B. Menentukan Hambatan Jenis Kawat Penghantar ()No. E

(volt)R

(ohm)P

(besi)D

(besi)L1 L2

1 2 1 2

1.


3.7. PENGOLAHAN DATA...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................


...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................


3.8. ANALISA...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................


3.9. TUGAS AKHIR1. a. Hitung besar Rx, Ry dan hambatan pengganti Rx dan Ry yang dihubungkan secara

seri dan paralel.

b. Berdasarkan hasil percobaan, tentukan hukum hubungan seri dan paralel padahambatan.

2. a. Hitung hambatan jenis kawat penghantar dari grafik antara R terhadap panjangkawat.

b. Dengan melihat literatur, tentukan jenis bahan kawat penghantar tersebut................................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................


2.10. KESIMPULAN...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

LAMPIRAN GAMBAR


bab iii. jembatan wheatstone(1).pdf

Documents