1. Home Electromagnetism

2. Home The Motor Effect 16/02/2016 Aim: To use Flemming’s Left Hand Rule To explain how a motor works To construct a motor

3. Home Fields Bar Magnets Single Science Only handout

4. Home Opposite Poles Single Science Only

5. Home Same Poles Single Science Only

6. Home Fields due to Current

7. Home Single Science Only Single Coil of WireSolenoid

8. Home Magnetic Field Lines There are magnetic field lines around every Magnet Electrical wire (with current flowing through it) Anything magnetic in the field will experience a force

9. Home Wire in a magnetic field

10. Home The Catapult (Motor) Effect

11. Home Motor Effect If a conductor carrying an electric current moves through magnetic field lines at right angles it will experience a force. A charged particle will experience the same effect

12. Home Fleming's left hand rule

13. Home Increasing the Size of the Force

14. Home The motor effect: true or false?

15. Home Coil in a Magnetic Field

16. Home How does an electric motor work?

17. Home DC electric motor simulation

18. Home Would the same strength motor be used in both of these? How can the strength of an electric motor be increased? How do we increase motor strength? increase the strength of the magnet increase the current flowing through the coil increase the number of turns on the coil Worksheet

19. Home The Motor Effect recap

20. Home Induction 16/02/2016 Aim: To observe and define induction To explain how electricity is generated

21. Home Inducing current in a wire

22. Home What is electromagnetic induction? Current Carrying Wire + Magnetic field = Motion Motion + Magnetic field = Current in Wire Changing Magnetic field = Current in wire If they are at right angles to each other

23. Home Inducing current in a coil

24. Home Induction If a magnet is moved near a coil of wire a current is induced in the wire Faster motion, bigger current Stronger magnet, bigger current More turns, bigger current Change direction of motion, change direction of current

25. Home Factors affecting induced current

26. Home How can motion produce a current?

27. Home A generator is a device that converts mechanical energy into electrical energy. It is the opposite of an electric motor. Power stations use generators to produce electricity on a large scale. Mechanical energy is provided by rotating turbines that can be powered by: What are Generators? high-pressure steam – in coal, oil, gas and nuclear power stations wind – in wind turbines falling water – in hydroelectric power stations

28. Home How do AC generators work?

29. Home AC generator simulation

30. Home Induction: true or false?

31. Home The voltage of an alternating current can be changed using a device called a transformer. The alternating current in the primary (input) coil produces an alternating magnetic field. What is a transformer? A transformer contains two coils that are wound around a soft iron core. iron core primary coil secondary coil This alternating magnetic field induces an alternating current in the secondary (output) coil.

32. Home The voltage induced in the secondary (output) coil depends on the number of turns on the primary and secondary coils. How does a transformer change voltage? A step-up transformer has more turns on the secondary coil and so increases voltage. A step-down transformer has fewer turns on the secondary coil and so decreases voltage.

33. Home How are transformers used to supply electricity?

34. Home Transformers Transformers are used to change the voltage from the Primary (input) to the Secondary (output) They only work with a.c. (alternating current) Input (Primary) Voltage=Number of Primary Turns Output (secondary) VoltageNumber of Secondary Turns Example Question: Input voltage = 230 V Primary turns = 10000 Secondary turns = 500 What is the secondary voltage? Worksheet

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37. Home http://intranet.stthomasmore.org.uk/resource/Absorb%2 0Physics/Absorb%20Physics%20for%20A- level/Absorb%20Physics%20for%20A- level/HTML/units/080300.html