8th Electricity Question Bank
  • 1. Which of the following best describes voltage?
A) Trying to stop a runaway shopping cart.
B) Pushing a shopping cart quickly down a hill.
C) Adding bigger wheels to a shopping cart.
D) Filling a shopping cart with groceries
  • 2. Current is measured in...
A) Ohms
B) Volts
C) Watts
D) Amps
  • 3. Bill has a 9 volt battery that puts out 5 amps. How many watts of power will his battery generate?
A) 95 watts
B) 45 watts
C) 14 watts
D) 9 watts
E) 4 watts
  • 4. If I charged two balloons by rubbing them against my shirt, then held them close together - What would most likely happen?
A) pop
B) repel each other
C) do nothing
D) attract each other
  • 5. Which of the following would be the best material to use to make a circuit?
A) nylon cord
B) cotton string
C) copper wire
D) plastic tubing
  • 6. The following diagram shows a circuit that WILL work.
A) False
B) True
  • 7. The following diagram shows a...
A) Parallel Circuit
B) Open Circuit
C) Series Circuit
D) Switch
E) Incomplete Circuit
  • 8. A turbine does this...
A) Converts electrical energy to mechanical energy
B) Converts mechanical (kinetic) energy to electrical energy
C) Converts chemical energy to electrical energy.
  • 9. One disadvantage of wind turbines is...
A) It costs farmers too much money to put them on their land.
B) The government taxes them a lot.
C) They generate low amounts of electricity (compared to coal), even on really windy days
D) They can kill birds in the area.
  • 10. An advantage of electric solar energy is...
A) It will not run out in our lifetime.
B) It can work in any location.
C) It produces electricity more efficiently than wind or coal.
D) It generates electricity 24 hours a day.
  • 11. Batteries do this...
A) Convert chemical energy to electric energy
B) Converts electrical energy to mechanical energy
C) Converts mechanical energy to electrical energy
  • 12. Describe two ways you can make an electromagnet stronger.
  • 13. Which fossil fuel source helps to generate the most electricity?
A) Oil
B) Natural Gas
C) Coal
  • 14. Why are our houses (and buildings) wired with parallel circuits?
  • 15. An advantage of natural gas is...
A) it does not pollute as much as oil or coal
B) It can be harvested from the air and then sold to others
C) It won't run out for 400-500 years according to estimates
D) It can be recycled over and over
  • 16. What could you do to blow out a lightbulb?
  • 17. The following diagram shows...
A) an open circuit
B) a parallel circuit
C) a detonator
D) a closed circuit
  • 18. Electricity is the flow of...
A) electricity
B) electrons
C) neutrons
D) protons
  • 19. If you compared the bulbs of a circuit with short wires and a bulb in a circuit with long wires, what would you expect?
A) The bulb with the longer wires would be brighter
B) The bulbs would be the same.
C) The bulb with the shorter wires would be brighter
  • 20. Security systems are usually wired this way.
A) Parallel
B) Jointly
C) Ampere
D) Series
  • 21. Describe some advantages of a parallel circuit.
  • 22. What could I do to increase the voltage in a circuit?
A) use longer wires
B) use bigger wires
C) use smaller wires
  • 23. Which bulb will be brighter?
A) Neither bulb will light up
B) The middle bulb
C) They will both be the same brightness
D) The bulb on the right
  • 24. Anytime you add a load (lightbulb, motor, etc) to a circuit it usually heats up. This is caused by...
A) Amperage
B) Watts
C) Resistance (ohms)
D) Voltage
  • 25. Explain why most electronic devices require DC power, not AC power. (2 points)
  • 26. If I wanted to convert electrical energy to mechanical (kinetic) energy, I would need this...
A) windmill
B) motor
C) turbine
D) static
  • 27. Your cell phone charger just broke off in the outlet. Metal wires are exposed. Explain how you would remove it safely.
  • 28. How are magnets used in turbines to generate electricity. Explain what the magnet does.
  • 29. These particles are on the move when electricity is flowing.
A) protons
B) quark
C) electrons
D) neutrons
  • 30. A particle with a positive charge.
A) neutrons
B) electrons
C) quark
D) protons
  • 31. This is an example of a...
A) series circuit
B) static circuit
C) open circuit
D) parallel circuit
  • 32. The type of current that comes into our house is...
A) DC power
B) AC power
C) CC power
D) AD power
  • 33. Bill is trying to make his motor go faster. Which of the following would give his the best results?
A) Add more coils to his wire.
B) Get a thicker wire
C) Get a thinner wire
D) Add a lightbulb to the circuit
E) Turn the magnet over
  • 34. Which of the following would be the best metal to use in a battery in terms of power and price?
A) Graphite
B) Aluminum
C) Pyrite
D) Lithium
E) Gold
  • 35. I have two batteries and one bulb and a bunch of wiring. If I am stuck on a desert island at night, how would I wire the circuit to increase the chances that a plane flying over head would find me. Explain why.
  • 36. You test three types of metals in a salt solution to see which ones produce the most voltage. You fill up six glasses with 200 mL of water. Next you shake in salt for about 5 seconds into each glass and stir it up. Next you test each of the metals and get the following results. Nickel and Copper = 4.5 volts, Nickel and Silver = 3 volts, Silver and Copper = 3.5 volts. What was potential source of error in this experiment?
  • 37. You have a motor that needs to be running constantly to run a fan that cools your computer. It is connected to two batteries that need to be removed every week to be recharged. How is your motor wired?
A) Parallel
B) Open
C) Series
  • 38. Bill has a lightbulb that requires 40 watts to light up. His power source puts out 12 volts and 4 amps. Will this be enough to power his lightbulb? Explain why or why not.
  • 39. Which computer should you not use with a charger that puts out 5 amps and 14 volts?
A) A computer that runs at 10 watts
B) A computer that runs at 40 watts
C) A computer that runs at 80 watts
D) A computer that runs at 70 watts
E) A computer that runs at 60 watts
  • 40. A circuit has two 1.5 volt batteries wired in series powering a single bulb. The bulb has a resistance of 3 ohms. What is the current? (Show your equation and numbers used)
  • 41. An alarm clock pulls 0.5 A of current in a 120 volt circuit. What is the resistance? (Show your equation and numbers used)
  • 42. How many volts are there in a circuit with 2 amps and a motor with 3 ohms of resistance? (Show your equation and numbers used)
  • 43. What is the load/resistor in this circuit?
A) Wires
B) Switch
C) Battery
D) Lightbulb
  • 44. If you smashed the on/off switch in this diagram, what would happen to the bulbs?
A) Neither of them would go out
B) Only one would go out
C) They would both go off
D) Both of them would stay on
  • 45. When the switch is turned on for this circuit, will the lights turn on? Tell if they will both turn on, one of them will turn on, or none of them will turn on. Explain why you think this is the case. (Hint - trace the electrons from the negative terminal of the battery, back to the positive).
  • 46. The iPhone 8 charges slower than previous versions due to a wattage restriction. Iphone 7s and below could handle 15 watts. If the new iPhone 8 uses a 5volt charger. What is the maximum current (amps) it can be charged with that won't exceed 7.5 watts?
A) 2 amps
B) 3.5 amps
C) 5 amps
D) 7.5 amps
E) 1.5 amps
  • 47. An XBox controller uses a single 1.5 volt battery. How much resistance does the controller have if the batteries have a current of .5 amps?
A) 3 volts
B) 2 ohms
C) .33 ohms
D) .75 ohms
E) 3 ohms
  • 48. A subwoofer needs 110V to push a current of 11 amps through it's coil. What is the resistance of the subwoofer?
A) 11 ohms
B) 10 ohms
C) 1100 ohms
D) 1000 ohms
E) 9 ohms
  • 49. A circuit has two 1.5 volt batteries and a 3 ohm resistor. What is the current?
A) 1 amp
B) .5 amp
C) 2 amps
D) 4.5 amps
E) 1.5 amps
  • 50. A toaster has 60 ohms of resistance and 2 amps of current. What is the voltage going through the toaster? (Just type in the number - no label)
  • 51. What happens when there is no resistance in a circuit?
A) switch
B) diode
C) photoresistor
D) short circuit
  • 52. Bill has a motion sensor that has 10 ohms of resistance and .5 amps of current. Using this information (and showing your work), tell the wattage used by the motion sensor. (Hint: You need to use two equations to get the answer. Solve one equation, then use your answer from that to complete the second equation).
  • 53. The picture below shows an example of a _________, which only lets electricity flow in a single direction:
A) photoresistor
B) capacitor
C) diode
D) switch
  • 54. Describe why you need an AC/DC converter for most electronics.
  • 55. A subwoofer needs 110V to push a current of 11 amps through it's coil. What is the resistance of the subwoofer?
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