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Remember each question will be in the form of an answer and you must respond with a question. GOOD LUCK Here are the categories May the Force be with You (Forces & Electrical Charges) Electrical Charge Carriers Don’t pick this category (Making Electricity Flow) Resistance is futile! (Resistance, current, & voltage) Knowledge is Power Shocking, but true? May the Force be with You (Forces & Electrical Charges) Electrical Charge Carriers Don’t pick this category (Making Electricity Flow ) Resistance is futile! (Resistance, current, & voltage) Knowledge is Power Shocking, but true? $100 $100 $100 $100 $100 $100 $200 $200 $200 $200 $200 $200 $300 $300 $300 $300 $300 $300 $400 $400 $400 $400 $400 $400 $500 $500 $500 $500 $500 $500 Unlike Charges _______ one another. attract Like charges _______ each other repel Name the two kinds of electrical charges. Positive & Negative (or proton and electron) In the Find Out Activity in section 1-1, you put 2 pieces of scotch tape on top of each other (then pulled) as well as put 2 pieces of tape on the desk side by side (then pulled). What happen when the tapes were brought close together and WHY? You caused the tapes to have an electrical charge. The tapes on top of each other had opposite charges and attracted each other. The tapes side-by-side had similar charges and repelled each other. Thales, a Greek who lived in 600 B.C., named the effects of electricity after the Greek word for Amber. What is that word? Elektron (electron) Give 3 examples of an insulator Paper, plastic, rubber, wood, glass Give 2 examples of a conductor Most metals (copper, aluminum, gold, silver), the Human Body What is a conductor. Define it. A material in which electrical charges move freely from place to place. Explain how/why a balloon will stick to a wall if charged? The uncharged wall is attracted to the charged balloon. The charges on the balloon repel the like charges on the wall’s surface. The remaining unlike charges are attracted to the charges on the balloon. The charge is enough to overcome gravity. Unless you insulate it, you cannot charge an aluminum comb by rubbing it with fur, wool, or silk because…. ….The charge flows away (through you holding it). I cannot hold a charge. It is a conductor so charges move freely from place to place. You and your hand are conductors so the charges flow through the balloon, into your hand/body. Potential difference in electrical energy is measured in ___(what units?) and is called ______. Volts and is called Voltage (or potential difference) How much electric charge flows past a point in a circuit during a given time is called _____. Current A complete path through which a charge flows is called _____. Circuit _____ is a property of materials that indicates how much energy changes to thermal energy and light as an electrical charge flows through the material. Resistance When we look at lightening and its charges, which has a positive charge and which has a negative charge in the initial formation of lightening? the stepped leader from the clouds ; OR the streamer from the ground? The stepped leader coming down from the cloud has a negative charge. The streamer going up from the ground has a positive charge. The relationship among current, resistance, and potential difference can be measured using __________’s Law Ohm’s Law A circuit has a battery (12 Volts), and a resistor (3 Ohms). What is the current of this circuit? 4 Amperes (amps) A circuit has a current of 5 Amps and 10 Ohms of resistance throughout it. What is the voltage of this circuit? 50 volts You observe that a very large voltage produces only a small current in a circuit. What can you conclude about the resistance of the circuit? The resistance is high. Would you connect a battery to a bulb with a thick or thin copper wire if you did not want the wire to become hot? Explain. A thick wire as a thin wire has greater resistance and would tend to get hot more readily than a thick wire. If a charged rod is brought near a small piece of uncharged aluminum foil, the foil will _____ a. not be attracted to the rod b. be repelled c. not be affected d. be attracted to the rod d. be attracted to the rod The difference in potential energy per unit charge between the two terminals of a battery is measured in a. ohms b. volts c. amperes d. watts b. volts If you are outside during a thunderstorm, which is the safest place to be in order to avoid being struck by lightning: near an iron fence, under a tree, or in a ditch? Why? The safest place is in a ditch because the lightning will strike the highest point, and the ditch is the lowest of the three What is the formula relating potential difference, current, and resistance? (AND who’s law is it?) Ohm’s Law: I=V/R, or V=IR, or R=V/I Two batteries produce a potential difference of 18V. A resistor is added with a resistance of 9 ohms. What is the current (use proper units as well!) Answer: 2 Amps I=V/R I= 18 Volts/ 9 ohms I = 2 Amperes Static electricity is the accumulation of _____. electrical charges A charge flows through a conductor _____. a.only if it is negatively charged. b.only if it is positively charged. c.only if there is no difference in potential. d.as an electric current. D. As an electric current. Electrons will flow through a lightbulb in a circuit as long as there is _____. a.no change in resistance b.no static discharge c.an open circuit d.a potential difference d.a potential difference Why is a lightning rod effective? When a lightning strike occurs, the rod provides a low-resistance path for the lightning charge to be conducted away from the structure. Also, the lightning rod may be the tallest structure, and lightning will take the shortest path to the ground. How can you demonstrate that there are two kinds of electrical charges? You can show two kinds of electrical charges by allowing objects that have a charge to interact. Objects having like charges will repel and objects having unlike charges will attract. Electricity, Baby! Would you expect a bulb to burn brighter, dimmer, or the same in a circuit after you removed one fourth of the total length of the electrical wire and then reconnected the circuit? Explain. The bulb should burn slightly more brightly because the shorter the wire (conductor), the lower the resistance. This would allow more current to give a brighter light. And the winner is…..