3.1 Electromagnetic Physic Form 5 Chapter 3

1. FORM 5
CHAPTER 3
ELECTROMAGNETISM

2. LEARNI NG AREA…
• 3.1 Analysing the Magnetic Effect of a
Current-carrying Conductor
• 3.2 Understanding the Force on a Current-
carrying Conductor in a Magnetic Field
• 3.3 Analysing Electromagnatic Induction
• 3.4 Analysing Transformers
• 3.5 Understanding the Generation and
Transmission of Electricity

3. 3.1 Analysing t he Magnet ic
Ef f ect of a Current -carrying
Conduct or
• Learning Out comes…
– st at e what an elect romagnet is.
– draw t he magnet ic f ield pat t ern due
t o a current in a:
i. st raight wir e, ii. coil, iii.
solenoid.
– plan and conduct experiment s t o
st udy f act ors t hat af f ect t he
st rengt h of t he magnet ic f ield of an
elect romagnet .
– describe applicat ions of
elect romagnet s.

4. Elect romagnet ism…
• I s a magnet made by winding coil of
insulat ed wire around a sof t iron
core, so t hat a magnet ic f ield is
produced when a current is passed
t hrough t he coil.
• Can be f ormed by winding about 20
t urns of insulat ed copper wire round
a sof t -I ron core such as a sof t -iron
nail.

5. Elect romagnet ism…

6. Elect romagnet ism…

7. • Straight Wire
Magnet ic Field Pat t ern &
Direct ion of t he Magnet ic Field
Due t o a Current …
• Straight Wire• Straight Wire
• Det ermines by
– Magnet ic Field in a St raight Wire
– Magnet ic Field in a Coil
– Magnet ic Field in a Solenoid

8. • Straight Wire
Magnet ic Field Pat t ern…
• Straight Wire• Straight Wire
• St raight Wire
– Two met hods t o det ermine direct ion
of t he magnet ic t he f ield:
• Right -hand gr ip r ule
• Maxwell’s scr ew r ule

9. • Straight Wire
Magnet ic Field Pat t er n…
St raight Wire
• Straight Wire• Right -hand grip
rule
The thumb aligns
with the current
flows while the
fingers determine
the magnetic field
direction.

10. • Straight Wire• Straight Wire• Straight Wire
• Maxwell’s screw
rule
The direction of
rotation of the screw
gives the direction of
the magnetic field if
the screw move
forward in the
direction of the
current in the wire.
Magnet ic Field Pat t ern…
St raight Wir e

11. Magnet ic Field Pat t ern…St raight
Wire

12. Magnet ic Field Pat t ern…
St raight Wir e
Current out - anticlockwise Current in - clockwise

13. Magnet ic Field Pat t ern…
Circular coil

14. Magnet ic Field Pat t ern…
Circular coil

15. Magnet ic Field Pat t ern…
Solenoid

16. Magnet ic Field Pat t ern…
Solenoid

17. Magnet ic Field Pat t ern…
Solenoid
Methods to determine the poles of a solenoid:

18. Magnet ic Field Pat t ern…
Solenoid
Methods to determine the poles of a solenoid:

19. Fact or s Af f ect ing t he St rengt h of t he
Magnet ic Field of an Elect romagnet

20. Fact or s Af f ect ing t he St rengt h of t he
Magnet ic Field of an Elect romagnet

21. Fact or s Af f ect ing t he St r engt h of t he
Magnet ic Field of an Elect romagnet

22. Fact or s Af f ect ing t he St r engt h of t he
Magnet ic Field of an Elect romagnet

23. Fact or s Af f ect ing t he St r engt h of t he
Magnet ic Field of an Elect romagnet

24. Applicat ion of Elect romagnet

25. Applicat ion of Elect romagnet

26. • Time to answer the questions……
– Mastery Practice 3.1
– Challenge Yourself
• Page 78 & 79