Title: Circuits and Ohms Law
1Circuits and Ohms Law
2Series Circuit
3Series Circuit
4Series Circuit
5Ohms Law
V I R
V
V
I
R
V
I R
R
I
6Battery 12 Volts
Headlight R 1.1?
Solve for current flow (I)
7Battery 12 Volts
Headlight R 1.1?
8Battery 12 Volts
Headlight R 1.1?
V
I
I 10.9 Amperes
R
12
I
1.1
9What is the value of R ?
I 0.33 A
V 9
t
R ?
10I 0.33 A
V 9
t
R ?
V
R
choose formula
I
Solution
11I 0.33 A
V 9
t
R ?
V
R
choose formula
I
9
Solution
R
substitute values
0.33
12I 0.33 A
V 9
t
R ?
V
R
R 27.27 Ohms
I
9
Solution
R
0.33
13What would change ifI 33mA?
I 33 mA
V 9
t
R ?
14I 0.033 A
V 9
t
R ?
Solution
V
R
R 272.7 Ohms
I
9
Less current is due to more resistance
R
0.033
15Series Circuit
R1
V
R2
t
16Series Circuit
R1 1K
V 9V
R2 560
t
What is the total resistance (Rtotal or Rt) in
this circuit?
17Series Circuit
R1 1K
V 9V
R2 560
t
Rtotal 1000 560 Rtotal 1560
18Series Circuit
R1 1K
V 9V
R2 560
t
What is the current (I) in this circuit?
19Series Circuit
R1 1K
I V/R I 9/1560 I 0.00577 Amperes I 5.77 mA
V 9V
R2 560
t
20Equivalent Series Circuit
R1
V
R2
t
21Equivalent Series Circuit
R2
V
t
R1
22Symbols - resistor
R1
R1
23Symbols - potentiometer
R4
R4
24Potentiometer Construction
carbon
2510K Potentiometer
Slide Control Linear Taper
10,000 ohms
2610K Potentiometer
Slide Control Linear Taper
1000 ohms
9000 ohms
2710K Potentiometer
3K ohms
7K ohms
2810K Potentiometer
6K ohms
4K ohms
2910K Potentiometer
9.9K ohms
100 ohms
3010K Potentiometer
0 ohms
10K ohms
3110K Potentiometer
0 ohms
10K ohms
10K ohms
3210K Potentiometer
6.7K ohms
3.3K ohms
3310K Potentiometer
5K ohms
5Kohms
3410K Potentiometer
3.3K ohms
6.7Kohms
3510K Potentiometer
0K ohms
10Kohms
36Potentiometer Circuit
50-Ohm Pot.
35 Ohms
12 VDC
How muchCurrent?
37Potentiometer Circuit
50-Ohm Pot.
35 Ohms
I V/R I 12/35 I 0.34 Amps
12 VDC
38Potentiometer Circuit
50-Ohm Pot.
10 Ohms
12 VDC
How muchCurrent?
39Potentiometer Circuit
50-Ohm Pot.
10 Ohms
I V/R I 12/10 I 1.2 Amps
12 VDC
40Potentiometer CircuitSchematic
R1 50?
12 VDC