21 3 Electrical Energy Generation and Transmission Assessment

Generating electric current �Electric current creates a magnetic field �LT #2: Demonstrate and explain

1. How is voltage induced in a conductor? �Conductors are materials through which charge

2. Name two types of generators. �AC = alternating current; charges flow in one

3. How does a transformer work? 1) A transformer increases or decreases voltage and

4. Name the 6 sources of electrical energy in the United States. �Coal �Nuclear

5. How can water be used to create electrical energy? �Water can turn a

6. What is the connection between Faraday’s law & the generation of electrical energy?

7. How are AC & DC alike? How are they different? �Both produce electric

8. Why can’t we use electrical energy directly from a high voltage line? �We’d

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21. 3 Electrical Energy Generation and Transmission Assessment Questions 1 -8

Generating electric current �Electric current creates a magnetic field �LT #2: Demonstrate and explain that an electric current flowing in a wire will create a magnetic field around that wire (electromagnetic effect) [Motors] �A magnetic field can be used to produce an electric current = electromagnetic Induction = generator effect �LT #3: Demonstrate and explain that moving a magnet near a wire will cause an electric current to flow in the wire (the generator effect) [Generators]

1. How is voltage induced in a conductor? �Conductors are materials through which charge can flow easily (metal wires) �Voltage is induced in a conductor by a changing magnetic field. �So if you move a magnet near a conductor electric current is generated

2. Name two types of generators. �AC = alternating current; charges flow in one direction then reverse direction & converts mechanical energy into electrical energy �LT #1: Demonstrate and explain that an electric current flowing in a wire will create a magnetic field around that wire (electromagnetic effect) �DC = direct current; the current that leaves the generator flows only in one direction �Most power plants use AC because sending power over long distances & DC causes too much heat in wires

3. How does a transformer work? 1) A transformer increases or decreases voltage and current of 2 linked AC circuits 2) It changes voltage and current by generating a changing magnetic field in one coil. 3) This field then induces a current in a nearby coil with a different # of turns. 4) We need transformers to step up power to send it over long distances & step down power to make it safe to use in homes

4. Name the 6 sources of electrical energy in the United States. �Coal �Nuclear power �Water = hydroelectric �Wind �Natural gas �Petroleum

5. How can water be used to create electrical energy? �Water can turn a turbine (PE KE mechanical) �The turbine turns an axle of a generator & produces electricity (mechanical electrical) �LT #1: Describe a situation where energy is transformed from one form to another.

6. What is the connection between Faraday’s law & the generation of electrical energy? �Faraday’s law = a voltage is induced in a conductor by a changing magnetic field �The relative motion of a magnet & a coil of wire will cause charges to flow in the wire generating electric current and electrical energy

7. How are AC & DC alike? How are they different? �Both produce electric current by rotation of wire coil in a magnetic field �In a DC generator current only flows in one direction

8. Why can’t we use electrical energy directly from a high voltage line? �We’d fry! �High voltages are dangerous & household devices are designed to use much lower voltages