Which particle in an atom has no electric charge associated with it? a. proton c. neutron b. electron d. nucleus Jun 12 9:28 PM The electrons in a metal sphere can be made to move by touching it with a charged object. This process is called: a. charging by induction. c. charging by contact. b. charging by friction. d. charging by grounding. 1
To give an electrically neutral object a negative charge, you must a. remove electrons from it. c. add electrons to it. b. add protons to it. d. remove protons from it. A positively charged rod is held below a neutral pith ball electroscope. Which statement best describes the induced charge on the pith ball? a. Negative charges will move to the top of the pith ball. b. Positive charges will move to the top of the pith ball. c. Negative charges will move to the bottom of the pith ball. d. Positive charges will move to the bottom of the pith ball. 2
A negatively charged rod is held near a neutral pith ball electroscope. Before the objects touch, they will one another. After the objects touch, they will one another. a. attract/repel b. attract/attract c. repel/repel d. repel/attract A neutral object is touched with a negatively charged rod. The object will become a. uncharged. c. grounded. b. negatively charged. d. positively charged. 3
Which particles in an atom have an electric charge associated with them? a. proton, electron, neutron c. proton and neutron b. electron A lightning flash is one of 4 methods electrically charged objects can be. a. charged positively. c. discharged. b. charged negatively. d. bonded. 4
Indicate whether the statement is true (A) or false (B) 11. Object A has a negative charge. It attracts object B. Therefore object B must have a positive charge. 12. A conductor transfers electrons very well. 13. When a charged object loses electrons it becomes positively charged. 14. Static electrical charges are produced whenever two different materials simply touch each other. 15. Copper wire is a good example of an insulator. 16. Exposing dry air to water moisture is an example of charging an object. 17. A safe place to be during a lightning storm is under a tree. 18. An atom consists of electrons, protons and neutrons. 19. Both positively and negatively charged objects attract neutral objects. 20. move. When an electric charge is transferred from one object to another, the protons Indicate whether the statement is true (A) or false (B) 1. Aluminum, nickel and gold are all good conductors. 2. Modern homes and businesses are electrically wired in series. 3. Lightning strikes a lightning rod before it strikes the house because the lightning rod is a better insulator. 4. Voltage is a term used to describe the electrical potential difference across a load. 5. Object A has a negative charge. It attracts object B. Therefore object B must have a positive charge. 6. A conductor transfers electrons very well. 5
When electrons are flowing through an electric circuit, the switch that controls the circuit must be a. open. c. off. b. closed. d. ready. The SI unit for measuring the electric potential difference of electrons is the a. ohm. c. joule. b. ampere. d. volt. 6
3. Which of the following devices is used to measure the current in a circuit? a. ohmmeter c. voltmeter b. ammeter d. resistor 4. The unit for measuring electrical resistance is the a. ampere. c. coulomb. b. volt. d. ohm. 7
. Where must the switch be located in a series circuit? a. Next to the positive terminal. b. Next to the negative terminal. c. Next to the load. d. Anywhere in the circuit. 6. Electric current is defined as a. the energy that the source gives electrons. b. the resistance of a conductor. c. how many electrons pass by a given point in a circuit. d. the energy the electrons transfer to the load. 8
Electric current is measured in a. joules b. volts c. amperes d. ohms e. watts The type of light bulb that uses the least amount of energy is: a. a fluorescent bulb. b. a halogen bulb. c. an incandescent bulb. d. an LED bulb. 9
Which of the following statements describes the current in a series circuit? The current is; a. the same at every point b. largest at the negative terminal c. largest through the load d. measured in ohms (Ω) e. largest at the positive terminal If three lights were attached in series, then; a. if one bulb stops working then they all stop working b. they would only work if all three lights were working c. the total voltage would be split three ways d. All of the above are true. 10
In three or four steps, show how a pith ball can get a negative charge through contact with a charged object. (5 marks) 1) A smoke detector is connected to a 9.0 V battery and draws a current of 30A. Calculate the resistance of the smoke detector. Be sure to use the correct format for solving word problems.(4 marks) 11
1) Draw a schematic diagram with four cells connected in series. Connect these to a series circuit which has a switch, a light and a resistor. (5 marks) 1) Draw a circuit diagram to show 3 cells connected in series. Connect a lamp in parallel to a switch and a resistor that are connected in series. Place a voltmeter in parallel with the resistor. (5 marks) 12
1) Examine the following circuit and answer the questions below (4 marks) a) If switch #1 is the only open switch which lights remain on? b) If switch #2 is the only open switch which lights remain on? c) If light bulb #3 burns out (all switches closed) which lights remain on? d) How could you turn on light bulb #1 by itself? Jun 13 9:18 AM 13