1. Pop Quiz: Magnetism and Electricity Joseph and Justin Room 101 April 21, 2008

2. Question 1  What is the stored source of electrical energy? A. Batteries Batteries B. Fuse C. Generator Generator D. Electric Motor Electric MotorElectric Motor

3. Answer 1 A. Batteries  Definition: a battery is a stored source of electrical energy that converts chemical energy into electrical energy  A fuse is a safety device in a circuit.  A generator is a device that converts mechanical energy into electrical energy.  An electric motor converts electric energy to mechanical energy.

4. Question 2  What does not allow electrons to flow freely? A. Circuit breaker Circuit breakerCircuit breaker B. Resistance Resistance C. Insulator Insulator D. Conductor Conductor

5. Answer 2 C. Insulator  Definition: An insulator does not allow electrons to flow freely.  A resistance is the amount of opposition to the flow of electricity.  A circuit breaker is a device that protects the circuit from being overloaded.  A conductor allows electrons to flow freely.

6. Question 3  What is used to measure the resistance in a current? A. Volt (voltage) Volt (voltage)Volt (voltage) B. Amps (amperes) Amps (amperes)Amps (amperes) C. Watts Watts D. Ohms Ohms

7. Answer 3 D. Ohms  Definition: Ohms measure the resistance in a current. The more ohms, the more resistance.  Volts measure the pressure of electrons.  Amps measure the battery’s current.  Watts measure the power (Volts x Amps= Watts).

8. Question 4  Where is the magnetic field strongest? A. Compass Compass B. Magnetic field Magnetic fieldMagnetic field C. Poles Poles D. Current Current

9. Answer 4 C. Poles  Definition: Poles are where the magnetic fields are strongest and magnets have two, one north and one south.  A compass is used to find the direction “North”.  A magnetic field is the space around a magnet where magnetic forces operate.  A current is the number of electrons flowing per second.

10. Question 5  What is the region inside a magnetic material called? A. Magnetic field Magnetic fieldMagnetic field B. Domain Domain C. Magnetic poles Magnetic polesMagnetic poles D. Magnetic force Magnetic forceMagnetic force

11. Answer 5 B. Domain  Definition: A domain is the region inside a magnetic material.  A magnetic field is a magnetic force around the area of a magnet.  Magnetic poles are used to attract other steel/iron objects.  Magnetic force is the force exerted between magnetic poles, producing magnetization.

12. Question 6  What uses the Earth’s magnetic field? A. Magnetite Magnetite B. Generator Generator C. Compass Compass D. Lodestone

13. Answer 6 C. Compass  Definition: A compass uses the Earth’s magnetic field to find direction.  Magnetite is a material with magnetic properties.  A generator is a device that converts mechanical energy into electrical energy.  Lodestone is a piece of magnetite that has magnetic properties and attracts iron or steel.

14. Question 7  What is the build-up of charges, the stationary charges that do not move? A. Static electricity Static electricityStatic electricity B. Parallel circuit Parallel circuitParallel circuit C. Series circuit Series circuitSeries circuit D. None of the above None of the aboveNone of the above

15. Answer 7 A. Static electricity  Definition: Static electricity is the build- up of charges, the stationary charges that do not move.  A parallel circuit has different parts on separate branches and currents can flow freely when there is a malfunction in an area.  A series circuit is connected on the same branch and can’t flow freely when there is a malfunction in an area.

16. Question 8  What uses an electromagnet to convert electrical energy to mechanical energy? A. Switch Switch B. Electric motor Electric motorElectric motor C. Generator Generator D. Compass Compass

17. Answer 8 B. Electric motor  Definition: A device that uses an electromagnet to convert electric energy to mechanical energy in order to do work.  A switch is a device that turns on/off a circuit.  A generator is the exact opposite of an electric motor.  A compass uses the Earth’s magnetic field to find direction.

18. Question 9  What is the push or pull between objects with different charges? A. Repel Repel B. Magnet Magnet C. Attract Attract D. Electrical Forces Electrical ForcesElectrical Forces

19. Answer 9 D. Electrical forces  Definition: An electrical force is the pull or push between objects with similar or different charges.  “Like” poles are used to repel magnets.  “Different” poles are used to attract magnets.  A magnet is an object that attracts/repels objects with iron/steel properties.

20. Question 10  What kind of circuit doesn’t stop flowing if one light bulb is destroyed? A. Short circuit Short circuitShort circuit B. Parallel circuit Parallel circuitParallel circuit C. Series circuit Series circuitSeries circuit D. Open circuit

21. Answer 10 B. Parallel Circuit  Definition: Parallel circuits are different parts on separate branches. Currents can flow evenly when there is a malfunction in one area.  A short circuit is the shortest path to the ground. It occurs when current follows a path other than the intended path. Sometimes this is the least safe path.  Series circuit are the opposite of parallel circuits.  An open circuit has at least one break so current will not flow.

22. Question 11  What is the measure of extra positive or negative particles? A. Volts Volts B. Watts Watts C. Kilowatt-hour Kilowatt-hour D. Charge Charge

23. Answer 11 D. Charge  Definition: A charge is the measure of extra positive or negative particles on an object.  Volts measure the pressure on electrons.  Watts measure the power of volts and amps together.  Kilowatt-hour is the measure of the electrical work done.

24. Question 12  What can turn on and off a circuit? A. Switch Switch B. Series circuit Series circuitSeries circuit C. Circuit breaker Circuit breakerCircuit breaker D. Short Short

25. Answer 12 A. Switch  Definition: A switch is used to create an opening in a circuit to stop the flow of electricity, or turn it on and off.  A series circuit can not turn on and off a circuit, but it does have a circuit that is all connected on the same branch.  A short causes electricity to flow in the shortest path.  A circuit breaker is a device that protects a device from being overloaded.

26. Question 13  What kind of charge moves to make a static charge? A. Positive charge Positive chargePositive charge B. Static electricity Static electricityStatic electricity C. Negative charge Negative chargeNegative charge D. Neutral charge Neutral chargeNeutral charge

27. Answer 13 C. Negative charge  Definition: A charge that can move from one object to another when two opposite objects are rubbed against each other.  A positive charge is a charge that does not move and waits for the other negative charges from the other object to come over.  Static Electricity is the movement of electrical charges from one object to another that stay on the object.  A neutral charged object has an equal number of positive and negative charges.

28. Question 14  What device protects a circuit from being overloaded? A. Circuit breaker Circuit breakerCircuit breaker B. Fuse Fuse C. Generator Generator D. Electric motor Electric motorElectric motor

29. Answer 14 A. Circuit Breaker  Definition: A device that protects any circuit from being overloaded.  A fuse is a safety device in a circuit.  A generator is a device that converts mechanical energy into electrical energy.  An electric motor converts electric energy to mechanical energy.

30. Question 15  How is Earth like a giant magnet? A. Earth has a north and south magnetic poles B. Earth has a huge magnetic field. C. Earth’s core is melted iron with electric currents flowing in the liquid iron. D.All of the above

31. Answer 15 D. All of the above Earth has a north and south magnetic poles, and a huge magnetic field. Earth’s core is melted iron with electric currents flowing in the liquid iron.  Earth is like a giant bar magnet with a north and south pole.  Earth’s gigantic magnetic field surrounds the entire planet.  Earth’s core is melted iron with electric currents flowing in the liquid iron.

32. Question 16  What is the most important part of a simple compass? A. magnet B. water C. sponge D. needle

33. Answer 16  Magnet You need a magnet to make a simple compass. When rubbed, the magnet will make the needle into a temporary magnet that can move freely to line up with Earth’s magnetic field.  Water allows the piece of sponge to turn freely.  A piece of sponge provides a space for the needle to rest.  The needle will only line up with Earth’s magnetic field once it is magnetized.

34. Question 17  How are electric current and magnetic fields related? A. Electric current produces magnetic fields B. Magnets in motion produce electricity C. Oersted and Faraday were friends D. Both A and B

35. Answer 17 D. Both A and B Electric current produces magnetic fields, and magnets in motion produce electricity.  In 1820, Hans Christian Oersted realized that the flowing electric charges caused a magnetic field.  In 1831, Michael Faraday discovered that moving a magnet inside a wire coil produced electric current.

36. Question 18  How can you make an electromagnet stronger? A. Use a thinner metal core B. Remove the metal core C. Add coils D. Spread apart the coils further from one another

37. Answer 18 C. Add coils  An electromagnet will be stronger if you add more coils.  A larger metal core will make the electromagnet stronger.  An iron core inside the coil will make the electromagnet stronger.  Close coils are stronger than ones spread apart from one another.

38. Question 19  What direction will a freely moving magnet seek? A. North North B. East East C. South South D. Towards the light Towards the lightTowards the light

39. Answer 19 A. North  Definition: The direction a freely moving magnet seeks.  South is another direction with a magnet that is free does not seek.  East is another direction which a freely moving magnet does not seek.  Towards the light is the direction dead people follow.

40. Question 20  How are electromagnets used in everyday life? A. In earphones B. In doorbells C. In motors In motorsIn motors D. All of the above All of the aboveAll of the above

41. Answer 20 D. All of the above Electromagnets can convert electrical energy to other forms of energy. Electromagnets also work with permanent magnets and wire coils to produce motion in motors and generators. The poles of the permanent magnet attract and repel the poles of the magnetic field.  Electromagnets in earphones change electrical energy into motion and sound.  The electromagnet in a doorbell transforms electricity into motion by pulling up the contact arm. This makes the clapper hit the bell, making sound vibrations.  The electromagnet in a motor uses electric current to create a magnetic field. The magnetic field near the rotor attracts and repels the rotor.

42. Results All 20- Thomas Edison 15-20- Benjamin Franklin 12-15- Magnetism Geek 10-12- Straight A Student 5-10- Need More Practice 2-10- New comer 0-2- Failed! Didn’t Study Restart Quiz

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