1. FIND CURRENT AND POWER USED BY R 1 SHOW ALL WORK 10V R 1 = 10KΩ USE OHM’S LAW TO FIND CURRENT FLOWING THRU R 1 FIND POWER USED BY R1 WE CAN SOLVE BY USING EITHER: 1. CONST 150 HOMEWORK#1 SOLUTIONS FIRST USING: OR USING:

2. FIND VOLTAGE AND POWER USED BY R1 SHOW ALL WORK I=5mA 10V R1R1 Since this is a series circuit with only one load R 1 The source (10V) and load R 1 voltages are the same. To solve for the power used by R 1. 2. CONST 150 HOMEWORK#1 SOLUTIONS

3. FIND TOTAL POWER USED BY THE 50Ω RESISTOR SHOW ALL WORK. GIVEN 10VR 1 = 50ΩI=200mA You can solve this problem 2 ways, by using either P=IV or P=I²R 3. CONST 150 HOMEWORK#1 SOLUTIONS

4. FIND THE POWER USED BY THIS 8Ω SPEAKER WHICH IS POWERED BY A 20VDC BATTERY SHOW ALL WORK 4. CONST 150 HOMEWORK#1 SOLUTIONS

5. SHOW ALL WORK 5. CONST 150 HOMEWORK#1 SOLUTIONS Three resistors are connected to a 10-V battery as shown in the diagram above. What is the current through the 2.0 Ω resistor? A.0.25 A B.0.50 A C.1.0 A D.2.0 A E.4.0 A SINCE THIS IS A SERIES CIRCUIT, IN SERIES CIRCUIT CURRENT IS THE SAME IN EACH ELEMENT. JUST SOLVE FOR I T USING OHM’S LAW AND WE HAVE THE ANSWER. CORRECT ANSWER IS C 10Ω 10V

6. 1.A 100 Ω, 120 Ω, and 150 Ω resistor are connected to a 9-V battery in the circuit shown above. Which of the three resistors dissipates the most power? A.the 100 Ω resistor B.the 120 Ω resistor C.the 150 Ω resistor D.both the 120 Ω and 150 Ω E.all dissipate the same power 6. CONST 150 HOMEWORK#1 SOLUTIONS

7. SINCE THE 2 RESISTORS ARE IN PARALLEL (120Ω and 150Ω) SOLVE FOR THE COMBINED RESISTANCE USING ; SOLVE FOR I T : 100Ω RESISTOR USES THE MOST POWER 0.25WATTS 6. SOLUTION FOR PROBLEM 6 CORRECT ANSWER IS A 9V RTRT CONST 150 HOMEWORK#1 SOULTIONS

8. I T= I 1= I 2+ I 3 FIND I 2,I 3, R T SHOW WORK 7. CONST 150 HOMEWORK#1 SOLUTIONS

9. TREAT THIS CIRCUIT AS SERIES- PARALLEL. FIRST FIND COMBINED RESISTANCE FOR THE 2 RESISTORS IN PARALLEL, IN A SERIES CIRCUIT ALL THE RESISTORS HAVE THE SAME CURRENT. SO, 7. SOLUTION FOR PROBLEM 7 FIND R T, THEN USE OHM’S LAW TO FIND I T CONST 150 HOMEWORK#1 SOULTIONS

10. HOW MUCH WILL IT COST TO RUN A 100W INCANDESCENT LIGHT BULB FOR 30 DAYS ? YOU ARE BILLED AT 3¢ PER KILOWATT-HOUR. HOW MUCH WILL IT COST TO RUN A EQUIVALENT 10W LED LIGHT BULB FOR 30 DAYS ? 30DAYSX24HRS=720 HRSX100W=72,000WATT-HOUR $ 30DAYSX24HRS=720 HRSX10W=7,200WATT-HOUR 8. ¢ CONST 150 HOMEWORK#1 SOULTIONS