1. Ohm’s Law

2. Ohm’s Law

3. Measuring Current Current is measured in unit amps (A)
In a series circuit, current is the same at all the points
In a parallel circuit, current is shared between all the points

4. What is the current? SERIES CIRCUIT PARALLEL CIRCUIT 3A 3A 4A 1A 4A 1A

5. Measuring Voltage
Voltage – the electrical push that a cell/battery gives to the current
Voltage is also known as Potential Difference
Voltage is measured in unit volts (V)

6. Measuring Voltage 3V
1.5V 3V
In a series circuit, voltage is shared between all the points
In a parallel circuit, voltage is the same at all the points

7. What is the current and voltage?
Series
Same
Shared
Parallel

8. What is the current and voltage?

9. Measuring Resistance
Resistance – slows down current, adding components to a circuit increases resistance
Resistance is measured in unit ohms (Ω)
More resistance = Less current = Less light
In a series circuit, add all resistors to get total

10. Electrical Power

11. What is the current?

12. What is the current?

13. What is the current?

14. How much voltage gives 5 amps of current through a 3 Ω light bulb?
I = V/R
V = (5A)  (3Ω)
V = 15V

15. How much current flows in a circuit with a 1
How much current flows in a circuit with a 1.5 volt battery and three 1 ohm resistances (bulbs) in series?
I = V/R
I = (1.5V) / (3Ω)
I = .5A

16. What is the voltage drop across each resistor in the circuit?
In a series circuit, voltage is shared between all the points
9V/3 = 3V

17. A light bulb with a resistance of 1. 5Ω is connected to a 1
A light bulb with a resistance of 1.5Ω is connected to a 1.5V battery in the circuit. Calculate the power used by the light bulb?
P = IV
I = V/R
I = (1.5V) ÷ (1.5Ω)
I = 1A
P = (1A)  (1.5V)
P = 1.5 W