* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Circuits - Pretty Good Physics
Survey
Document related concepts
Negative resistance wikipedia , lookup
Galvanometer wikipedia , lookup
Thermal runaway wikipedia , lookup
Schmitt trigger wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Operational amplifier wikipedia , lookup
Power electronics wikipedia , lookup
RLC circuit wikipedia , lookup
Power MOSFET wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Surge protector wikipedia , lookup
Electrical ballast wikipedia , lookup
Current source wikipedia , lookup
Current mirror wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Transcript
Circuits Created by Craig Smiley (Harrison HS, West Lafayette, IN) Supported by grant PHY-0851826 from the National Science Foundation and by Purdue University Lesson 1 – Ohm’s Law Simple Circuit Jumper cables Simplified Model of a Battery According to this model of a battery, which illustration would show a “dead” battery? A. B. C. D. None of these • Chemical Reaction Rechargeable Battery When you are “recharging” a rechargeable battery, what is going on? A. More electrons are being added to the battery (kind of like filling up your gas tank with more gasoline) giving it more charge. B. The chemical reaction is made to reverse sending the electrons back over to the negative side giving it more energy. C. Both of these D. Neither of these Current What does current measure? A. How fast the electrons are flowing past a certain point. B. How many electrons are flowing past a certain point in one second. C. Both of these D. Neither of these Speed of Electron You turn on a light switch and the light comes on. How fast do electrons travel through the wire? A. It is instantaneous (infinite speed) B. The speed of light C. Not quite the speed of light, but close D. Really slow Current Which way is current flowing around this circuit? A. Clockwise B. Counter-clockwise C. Both A & B D. Neither A or B E. Can’t be determined Voltage & Current Cause and Effect: what causes what? A. Voltage causes Current B. Current causes Voltage C. They cause each other (the chicken & the egg) D. Neither cause the other Current Rank the amount of current at different points around the circuit, from greatest to least. A. 1 > 2 > 3 > 4 > 5 B. 1 = 2 > 3 > 4 = 5 C. 1 = 5 > 2 = 4 > 3 D. 1 = 2 = 3 = 4 = 5 E. None of these Electrons What happens to the electrons once they get to filament? A. They are converted into light (the electrons are consumed) B. They slow down C. They lose electric potential energy D. Two of these (A-C) E. All of these (A-C) Potential Drop A “potential drop” or a “voltage drop” is a section of a circuit where energy is used, causing the electric potential to decrease across two different points along the circuit. Between what two points is there the biggest potential drop? A. Across A to B B. Across B to C C. Across C to D D. Across D to A Potential Gain A “potential gain” or a “voltage gain” is a section of a circuit where energy is given, causing the electric potential to increase across two different points along the circuit. Between what two points is there the biggest potential gain? A. Across A to B B. Across B to C C. Across C to D D. Across D to A Incandescent Light Bulbs In an incandescent light bulb is a filament, which is a really skinny piece of wire (made of tungsten) that is wrapped in tight coils. Which had more resistance in your circuit, the thicker copper wire or the filament? A. Thick wire B. Skinny filament C. Both had the same D. Neither had resistance E. Can’t be determined Incandescent Light Bulbs At first the circuit is open and the light bulb is off and then the circuit is closed and the light bulb turns on. During the first few seconds, what happens to the temperature of the filament, and what happens to the filament’s resistance because of that? A. The temperature of the filament increases causing its resistance to increase B. The temperature of the filament increases causing its resistance to decrease C. The temperature of the filament decreases causing its resistance to increase D. The temperature of the filament decreases causing its resistance to decrease E. The temperature of the filament doesn’t change and the resistance stays the same. Outlets Probably all of the exposed outlets around your house are rated at 120V. What does that mean? A. 120V will come out if you complete the circuit by plugging something in. B. 120V is the rate at which electrical energy will be used if you plugged something in. C. 120V is the difference of the electric potential from one hole of the outlet to the other. D. Two of these E. None of these Getting Shocked When power lines say HIGH VOLTAGE!, why is that dangerous if you touched it? A. A lot of Voltage would flow through you B. A lot of Current would flow through you C. A lot of both Voltage and Current would flow through you D. None of these Getting Shocked Why can birds sit on a power line and not get fried? A. They are not touching the ground B. There is not a difference in electric potential across their feet C. They are only holding on to one wire D. Two of these (A-C) E. All of these (A-C) Dimmer Switch One of your lamps has a dimmer switch on it. As you turn the dimmer switch up, making the light brighter, what changes occur in these measurements for the entire circuit? A. ΔV:same R:↑ I:↑ B. ΔV:same R:↓ I:↑ C. ΔV:↑ R:↓ I:↑ D. ΔV:↑ R:↓ I:same E. None of these Short Circuit What happened if the circuit is wired this way and why? A. The wire will get hot because the Voltage is high B. The wire will get hot because the Current is high C. The wire will get hot because both the Voltage and Current are high D. Nothing because there is no Voltage E. Nothing because there is no Current Simple Circuit What changes would occur in these measurements for the entire circuit if you changed the short circuit to now include the light bulb? A. ΔV:↑ R:↑ I:↑ B. ΔV:↑ R:↑ I:same C. ΔV:same R:↓ I:↑ D. ΔV:↓ R:↑ I:↓ E. None of these Jumper Cables Why was I not shocked with the jumper cables? A. My head had too much resistance so the voltage wasn’t strong enough to cause a substantial current. B. My head had too much resistance so the current wasn’t strong enough to cause a substantial voltage. C. My head decreased the voltage so there wasn’t a substantial current. D. My head decreased the current voltage so there wasn’t substantial current. E. None of these Short Circuit What happens if you had the simple circuit and then you added an additional wire to it as shown below. What would happen to the light bulb? A. B. C. D. It would stay on just as bright It would stay on, but ½ as bright It would turn off None of these Lesson 2 - Power 4 Light Bulbs Power Which light bulb is going to be brighter when plugged into a 120V outlet? A. 60 W B. 100 W C. Same D. Can’t be determined Power Which would be the correct equation for Power that would incorporate only current and resistance after combining ΔV=IR and P=IΔV? A. 𝑃 = 2𝐼𝑅 B. 𝑃 = 𝐼2 𝑅 C. 𝑃 = (𝐼𝑅)2 D. 𝑃 = 1 𝑅 E. None of these Power Which would be the correct equation for Power that would incorporate only voltage and resistance after combining ΔV=IR and P=IΔV? A. 𝑃 = (∆𝑉)2 𝑅 B. 𝑃 = (∆𝑉)2 𝑅 C. 𝑃 D. 𝑃 𝑅 = (∆𝑉)2 1 = 𝑅 E. None of these Power (∆𝑉)2 , 𝑅 Based off of 𝑃 = what would cause the Power of an appliance to increase? i. ii. iii. iv. A. B. C. D. E. If voltage stayed the same and resistance increased If voltage stayed the same and resistance decreased If resistance stayed the same and voltage increased If resistance stayed the same and voltage decreased i & iii i & iv ii & iii ii & iv None of these Power Based off of the equation P=I2R, which would cause a greater increase in Power? A. If current stayed the same and resistance increased by a certain amount B. If resistance stayed the same and current increased by the same certain amount C. Both would have the same effect D. Can’t be determined Power In a simple circuit where a resistor is connected to a battery, what would happen to the Power dissipated by the resistor if the resistance of the resistor was increased? A. Increase B. Decrease C. Stay the same D. Can’t be determined Power You have a simple flashlight circuit with a single 6 V battery. You try two different bulbs. Bulb #1 glows brightly. Bulb #2 glows dimly. Which bulb has the larger resistance? (The brightness is an indicator of Power dissipated by light bulb.) A. Bulb #1 B. Bulb #2 C. Can’t be determined Electric Bill What do Electric Companies sell us? A. Power B. Energy C. Current D. Voltage E. All of these Lesson 3 – Series Discovery with Christmas tree lights Series Rank the amount of current at these locations around this series circuit from greatest to least. A. 1 > 2 > 3 > 4 > 5 B. 1 > 2 > 3 = 4 > 5 C. 1 > 5 > 2 > 3 = 4 D. 5 > 1 > 4 > 2 = 3 E. 1 = 2 = 3 = 4 = 5 Series If one of the resistors was taken away, what would happen to the current coming from the battery? A. Current would decrease B. Current would stay the same C. Current would increase D. Can’t be determined Series What is the current going through the 4Ω resistor if the circuit is hooked up to a 24V battery? A. 2 A B. 6 A C. 8 A D. Can’t be determined E. None of these Series What is the potential drop across the 4Ω resistor if the circuit is hooked up to a 24V battery? A. 2 V B. 6 V C. 8 V D. Can’t be determined E. None of these Series Which resistor has the greatest potential drop across it? A. 3 Ω B. 5 Ω C. 4 Ω D. All have the same E. Can’t be determined Series If these resistors were light bulbs, rank the order of brightness, from bright to dim. The brightness is indicator of the Power dissipated. A. 5 > 4 > 3 B. 3 > 4 > 5 C. 3 > 5 > 4 D. 3 = 5 = 4 E. Can’t be determined Series What is the Power dissipated by the entire circuit? A. 2 W B. 36 W C. 48 W D. Can’t be determined E. None of these Lesson 4 – Parallel Circuits Day 1 – Christmas tree light discovery Day 2 – Fuses Parallel If another resistor was added in parallel, what would happen to the voltage across the 80Ω resistor? A. Increase B. Stay the same C. Decrease D. Can’t be determined Kirchhoff’s Loop Rule Parallel Which resistor has the most current flowing through it? A. 70 Ω B. 90 Ω C. 80 Ω D. All have the same E. Can’t be determined Parallel If these resistors were light bulbs, rank the order of brightness, from bright to dim. The brightness is indicator of the Power dissipated. A. 70 > 80 > 90 B. 90 > 80 > 70 C. 80 > 90 > 70 D. 80 = 90 = 70 E. None of these Parallel How much current is going through the 2Ω and 3Ω resistor respectively? A. 6A & 4A B. 1/6 A & 1/4 A C. Both have 12/5 A D. Both have 24/5 A E. Both have 72/5 A Parallel What is the total current coming from the battery? A. 12/5 A B. 5 A C. 6 A D. 4 A E. 10 A Water Tower Analogy If you put another hole in the water tower and added another pipe with kinks in it, what would happen to the rate at which water draining from the water tower? A. Increasing B. Decreasing C. Staying the same D. Can’t be determined Parallel If another resistor was added in parallel, what would happen to the total current? A. Increase B. Stay the same C. Decrease D. Can’t be determined Kirchhoff’s Loop Rule Parallel If another resistor was added in parallel, what would happen to the equivalent (total) resistance of the circuit? A. Increase B. Stay the same C. Decrease D. Can’t be determined Parallel Rank which point has the most current flowing through it, from greatest to least. A. 1 > 3 > 2 B. 1 > 2 > 3 C. 3 > 2 > 1 D. 1 = 2 = 3 E. None of these Kirchhoff’s Junction Rule Parallel Rank which point has the most current flowing through it, from greatest to least. A. 1 > 3 > 2 > 4 > 5 B. 1 > 3 > 4 > 2 > 5 C. 1 > 3 = 4 > 2 > 5 D. 1 = 5 > 3 = 4 > 2 E. None of these Parallel Rank which point has the most current flowing through it, from greatest to least. A. 1 = 5 > 2 = 4 > 3 B. 3 > 1 = 5 > 2 = 4 C. 5 > 4 > 3 > 1 > 2 D. 5 > 3 > 1 > 4 > 2 E. None of these Parallel If another resistor was added in parallel, what would happen to the current being drawn from the battery (point 2 compared to point 1)? A. Increase B. Stay the same C. Decrease D. Can’t be determined House Wiring How are the appliances in your house wired? A. Series B. Parallel Lesson 5 – Combination Circuits Unscrew light bulbs Combination Circuits Which of these schematic diagrams represent the same circuit? A. B. C. D. E. F. 1&2 1&3 1&4 2&3 1, 2, & 3 1, 2, & 4 The 6Ω resister has 2A of current flowing through it. How much current is flowing through the 4Ω resistor? A. B. C. D. E. 4/3 A 2A 3A 6A 12 A