Download presentation
Presentation is loading. Please wait.
Published byClifford Richard Modified over 9 years ago
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
35
Home ???????
36
Home USE ME IN THIS PRESENTATION
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
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.