1. Electrical Calculations

2. Ohm’s law describes the relationship between current, resistance, and voltage. As voltage increase, current increases As resistance decreases, current increases

3. Electric power is the rate at which electrical energy is changed into other forms of energy Power is measured in WATTS

4. Electrical energy is electric power multiplied by time. It is usually expressed in kilowatt-hours. A KILOWATT is 1000 watts! Find these at your house! They show the power company how much electrical energy you use.

5. Self-Check

6. Question 1 As resistance goes up, what happens to the current? a. The current goes up. b. The current goes down. c. The current stays the same. d. The current disappears.

7. Question 1 As resistance goes up, what happens to the current? a. The current goes up. b. The current goes down. c. The current stays the same. d. The current disappears.

8. Question 2 What is the rate at which electrical energy is changed into other forms of energy? a. electric power b. voltage c. electrical energy d. amps

9. Question 2 What is the rate at which electrical energy is changed into other forms of energy? a. electric power b. voltage c. electrical energy d. amps

10. Question 3 What is the voltage if the current is 4 A and the resistance is 10 Ω? a. 4 V b. 40 R c. 10 V d. 40 V

11. Question 3 What is the voltage if the current is 4 A and the resistance is 10 Ω? a. 4 V b. 40 R c. 10 V d. 40 V

12. Question 4 How much electrical energy does a 75 W light bulb use if it is on for 4 hours? a. 150 kWh b. 150 W c. 300 kWh d. 300 W

13. Question 4 How much electrical energy does a 75 W light bulb use if it is on for 4 hours? a. 150 kWh b. 150 W c. 300 kWh d. 300 W

14. Question 5 In the formula P = V X I, what does the I stand for? a. current b. intensity c. voltage d. resistance