176
Mudah dan Aktif Belajar Fisika untuk Kelas X
B
4B40=60=
B
7010B0=94=8A0:78 7010B0=94=8AC;0C;0
:458A84=AC7C7010B0= ?4B01070= AC7C H
;47:04=07010B0=A410=38=634=60=7010B0=94=8A ?4=60C7AC7CB47030?7010B0=9C6030?0B38BC;8A
t 2
K
- 8;08010B0= 4=8A?030 H
;C8=8C 4A8
0A 40:
;0B8=0 41060
C=6AB4= 8:
01= 40=8C
8;8:= 020
.42
L
K
L
K
L
K
L
K
L
K
L
K
L
K
L
K
K L
K
KL
K
K K
Sumber:
Physics, 2000
8;08 7010B0= 94=8A 14140?0 1070= 38148:0= ?030 - 010B0= 94=8A AC0BC ?4=670=B0 1460=BC=6 ?030 AC7C ?4=670=B0
B4A41CB42000B40B8A7C1C=60=0=B007010B0=94=8A30=AC7C 38?4;47308
t
430A0:0=,46433, =3030?0B4?4;47:4A8?C; 0=107E0A40:8=?0=90=6:0E0B7010B0==F0A40:8=14A04A8?C;
0=8=830?0B38BC;8A:0=30;014=BC:148:CB 4;08= 8BC A40:8= 14A0 ;C0A ?4=0?0=6 :0E0B A40:8= :428;
7010B0=:0E0BB4A41CB30?0B38BC;8A:0=30;014=BC:148:CB
8:0 :43C0 :4A8?C;0= B4A41CB 38601C=6:0= 0:0= 38?4;47 ?4A000=148:CB
K 4;08=1460=BC=6?030 30=9C601460=BC=6?03094=8A70
10B0= 4=8A?4=670=B0B4A41CB38E0:8;8;47AC0BC14A00=7010B0= 94=8A
7010B0=94=8A30?0B38BC;8A:0=A410608148:CB
177
Listrik Dinamis
B
K
4=BC:0= 7010B0= A410B0=6 0;C8=8C F0=6 ?0=90=6=F0 2 30= ;C0A ?4=0?0=6=F0 2
38:4B07C8 L
K
8:0:43C0C9C=610B0=6 0;C8=8C381481430B460=60=A414A0
L
K
,140?0:070CAF0=64=60;8 30;0?4=670=B00;C8=8CB4A41CB
7 2
L
K
2 L
K
L ,
+=BC:4=4=BC:0=:0E0B?4=670=B00;C8=8C386C=0:0=?4A000=
K K
L L
L
K
430A0:0=C:C7
41C07B44B4308:0E0BBC=6AB4=48;8:87010B0= ?030AC7C H
30=7010B0==F04=9038 ?030A00BAC7C
H4=BC:0=;07AC7CF0=6
38BC=9C::0=B44B4B4A41CB:4B8:07010B0=:0E0B=F0
7
8:4B07C8 H
2
H
2
4;0;C8?4A000=?4C1070=7010B0=14A07010B0=94=8A0:0=38?4;47
K H
L
K
H
K
4B8:07010B0=:0E0B=F0 AC7C=F0030;07
K
K L
H A478=660
K H
K H H
038AC7CF0=638BC=9C::0=B44B4030;07 H
aluminium V
I A
Contoh
8.6
Contoh
8.7
4B40=60=
2
7010B0=0:78 7010B0=C;0C;0
2
K K
L
, L
0380CAF0=64=60;830;0?4=670=B0 0;C8=8C030;07
Tes Kompetensi Subbab
B
2+,--.5,5-4 40?0:07:C0B0CAF0=64=60;8?030A41C07
?4=670=B0F0=648;8:87010B0= 98:038148
B460=60=A414A0 D;B 41C07:?=4=;8AB8:38148B460=60= D;B
A478=6604=60;8:0=0CA 40?0:07:C0B0CA
F0=64=60;8?030:?=4=B4A41CB98:038148 B460=60=
D;B
Kata Kunci
• beda potensial
• hambatan resistor
• hambatan jenis
• koefisien suhu hambatan
178
Mudah dan Aktif Belajar Fisika untuk Kelas X
470B8:0=60100=6:080=148:CB8=8
4=BC:0=14A0=F0 98:0,
030;07
D;B
C. Rangkaian Seri dan Paralel
030AC11018=8=300:0=4?4;09080=6:080=A4830=?00;4; :?=4=:?=4= ;8AB8: 470B8:0= A8AB4 8=AB0;0A8 ;8AB8: 38
C07C0?C:?;8AB8:A4B8:0;8AB8:B4;4D8A8038:?CB4 30=??0084C?0:0=0;0B0;0BC07B0=660F0=64=66C=0:0=
;8AB8: A410608 AC14 4=468=F0 ;0B0;0B ;8AB8: B4A41CB 380=6:08 A4348:80=C?0A478=6600;0B0;0BB4A41CB30?0B38=F0;0:0=30=380B8
:0=0A8=60A8=6B0=?0A0;8=64=660=66C0;0B0;0B;8AB8:;08=410608 2=B7=30A430=64==B=B4;4D8A881CA430=64=F4B8:030=0F07
A430=6 0=38 ;0B0;0B ;8AB8: F0=6 A430=6 14?40A8 A00B 8BCF08BC B4;4D8A8A4B8:0;8AB8:30=??008?0F0=6B49038:4B8:081C4
0B8:0=A4B8:0;8AB8:?0:07B4;4D8A830=??0089C600B84=BC B830:1C:0=4=60?0348:80=
=B7B4A41CB 4C?0:0= A0;07 A0BC :4C=BC=60= ?4=66C=00= 0=6:080=?00;4;30;040=6:080;0B0;0B;8AB8:06080=098:00;0B
0;0BB4A41CB380=6:08A480;04?4;09080=6:080=A4830=?00;4; =3010B0A8?4=66C=00=:?=4=:?=4=;8AB8:F0=6386C=0:0=
0;070;8=8=300:0=4=66C=0:0=4A8ABA410608:?=4=;8AB8:=F0
1. Hukum I Kirchhoff
414;C4?4;0908;418790C74=64=08C:C827755;0:C:0=;07 :4680B0=148:CB
0A8;?42100=38?4;47 6058:7C1C=60=B460=60=
30=:C0B0CA?030A41C07 4A8ABA4?4B8?0306010
148:CB 8:0
D;BB4= BC:0=14A0:C0B0CAF0=6
4=60;8 0860100=6:080=?030A0;=B4=BC:0=
14A0=F0 30=
V volt
I ampere
0,02 3
Aktivitas Fisika 8.3
Hukum I Kirchhoff Tujuan
Memahami Hukum I Kirchhoff.
Alat-Alat Percobaan 1.
Amperemeter DC 0 – 1 A, 2.
Tiga lampu kecil masing-masing 1,5 V 3.
Sebuah baterai 1,5 V 4.
Kabel penghubung secukupnya.
Langkah-Langkah Percobaan 1.
Susunlah peralatan seperti pada gambar, letakkan amperemeter di posisi A
1
2. Amatilah, apakah semua lampu menyala?
3. Catat kuat arus yang ditunjukkan amperemeter, kemudian pindahkan
amperemeter ke posisi A
2
, A
3
, dan A
4
. 4.
Catat kuat arus yang ditunjukkan amperemeter pada semua posisi tersebut 5.
Apakah A
1
dan A
2
menunjukkan angka yang sama? 6.
Jumlahkan angka yang ditunjukkan oleh A
3
dan A
4
. Apakah hasil penjumlahannya sama dengan angka yang ditunjukkan oleh A
1
atau A
2
? 7.
Apa kesimpulan Anda dari kegiatan ini?
Perjanjian cara penggambaran baterai sumber potensial DC pada
rangkaian adalah sisi yang lebih panjang menandakan kutub
positifnya.
Ingatlah
+ –
A = amperemeter P
A
3
A
4
A
2
A
1
50 mA 150 mA
60 mA A
B I
2
I
3
C I
1
R
1
R
2
R
3
179
Listrik Dinamis
08:4680B0=B4A41CB38?4;47:4A8?C;0=B4=B0=6C:C827755 33+0-141C=F83+0311206,+13.132322
.0 ,,1+,,3+0311206,30022 ,201 32 C:C8=84C?0:0=?4=F0B00=;08=3087C:C:4:4:0;0=C0B0=F0=6
4=F0B0:0=107E09C;07C0B0=F0=64=60;8B830:14C107 470B8:0=.2
010B4A41CB4=C=9C::0=14140?00CA
;8AB8:F0=6:4;C00AC:308AC0BCB8B8:?42010=60=4AC0834=60= C:C8277550:0=14;0:C
Gambar 8.6
Arus listrik yang memasuki dan keluar dari titik percabangan O.
0AC: :4;C0
4=60=348:80=?030.2
14;0:C
470B8:0=6010148:CB
4=BC:0=00730=14A0:C0B0CA;8AB8: 7
430A0:0=6010B430?0B3C0B8B8:2010=6F08BCB8B8:30= I +=BC:B8B8:2010=68A0;:0=0CA?0302010=648;8:8007:4;C0308
B8B8:2010=6 430A0:0=C:C827755
masuk keluar
I I
038 14007308:4
I +=BC:B8B8:2010=68A0;:0=0070AC::4B8B8:2010=6 430A0:0=C:C827755
I I
masuk keluar
038K B0=30=460B85K4=C=9C::0=107E00071C:0=0AC:B4B0?8:4;C0308
B8B8:2010=6
2 A 8 A
4 A P
Q 4 A
6 A I
2. Rangkaian Seri Resistor
41C070=6:080=;8AB8:38A41CB0=6:080=A4898:030;00=6:080= B4A41CB70=F0030A0BC;8=B0A0=F0=638;0;C80CA;8AB8:0300=6:080=
A48:C0B0CA;8AB8:F0=64;0;C8A4B80?:?=4=A0014A0E0;0C?C= 7010B0=A4B80?:?=4=141430.24=C=9C::0=0=6:08
0=A48308B8601C07;0?C?890 4:00=6?470B8:0=.2460=60=?030C9C=6C9C=6
30= 030;07
30= A430=6:0=B460=60=BB0;0=B00B8B8:30=
030;07 +=BC:7010B0=7010B0=F0=638ACAC=A4814;0:C
Gambar 8.7
Rangkaian seri tiga buah lampu pijar.
Contoh
8.8
I
1
I
2
I
3
I
4
I
5
O
K
Gambar 8.8
Susunan seri hambatan a
b R
1
R
3
V
1
V
2
V
3
R
2
7010B0=A4B80?:?=4=141430
180
Mudah dan Aktif Belajar Fisika untuk Kelas X
1 ,
BB
K
K
K ;47:04=0
30=
2-2
A478=660
+=BC:,1C077010B0=14;0:C
4A000=?4A000=148:CBC=BC:4=F43470=0:0=30=4?4 C307?4=F4;4A080=470B8:0=.2
0 8:0B430?0B7010B0=38ACAC=A4814;0:C K
K 1 0=6:080=A48145C=6A8A410608?41068B460=60=
BB BB
K
Gambar 8.9
Rangkaian seri dua buah hambatan.
3. Rangkaian Paralel Resistor
8:0AC0BC0=6:080=;8AB8:4148:0=;4187308A0BC;8=B0A0=C=BC: 0;80=0CA;8AB8:=F00=6:080=B4A41CB38=00:0=0=6:080=?00;4;
030 0=6:080= ?00;4; B460=60= ?030 A4B80? :?=4= A00 14A0 E0;0C?C=7010B0=A4B80?:?=4=141430
4140?0;0?C?890F0=638ACAC=A4200?00;4;B0?0:?030. 20=6:080=?00;4;145C=6A8A410608?410680CA
4?4B8 F0=6 B4;07 =30 ?4;0908 ?030 C:C 827755 ?030 .2:C0B0CA;8AB8:F0=64;0;C8
30= 030;07
30= 30?C=:C0B0CA0=B00B8B8:30= 030;070300=6:080=
?00;4;14;0:C
R
1
R
2
V V
1
V
2
V
2
K ;47:04=0
30=
.
4=60=348:80=
.
C=BC:,1C077010B0=14;0:C
. ,
...
Gambar 8.11
Susunan paralel hambatan I
1
R
1
R
2
R
3
I
2
I
3
I I
a b
Gambar 8.10
Susunan paralel tiga buah lampu pijar
K
K
