The document discusses electrical conductivity in materials. It explains that conductors allow electricity to flow through due to free electrons in their outer orbital shells. Insulators do not allow electricity to flow because there is a large forbidden energy gap between their valence and conduction bands, preventing electron movement. Semiconductors have properties between conductors and insulators, with a small forbidden gap that allows some electron movement when certain conditions are met. Electrical conductivity depends on the electronic structure and availability of free electrons in the material.

1. WIRE

2. WIRE
COPPER

3. WIRE

4. Open circuit
WIRE

5. CONDUCTORS
• The materials that allow the electricity to flow through them
• This property of conductors is known as conductivity.

6. CONDUCTORS
• Human body and earth are conductors

7. INSULATOR
• Materials that do not permit electricity to flow through them.

8. SEMICONDUCTOR
• Materials which have a conductivity between conductors and insulators.
SILICON CARBON GERMANIUM GALLIUM
ARSENIDE

9. WHY ELECTRICAL CONDUCTIVTY DIFFERENT
MATERIAL SMALL PARTICLES
ATOM

10. ATOMIC STRUCTURE
EDGE OF NUCLEUS
1ST ENERGY LEVEL BAND
2ND ENERGY LEVEL BAND
3RD ENERGY LEVEL BAND
R2
R1
R3
R1
R2 R3

11. ENERGY BANDS IN SOLID
EDGE OF NUCLEUS
1ST ENERGY LEVEL BAND
2ND ENERGY LEVEL BAND
3RD ENERGY LEVEL BAND
R2
R1
R3
THE OUTERMOST ORBIT ELECTRONS
ARE CALLED VALENCE ELECTRON
EDGE OF NUCLEUS
VALANCE BAND

12. ENERGY BANDS IN SOLID
EDGE OF NUCLEUS
1ST ENERGY LEVEL BAND
2ND ENERGY LEVEL BAND
3RD ENERGY LEVEL BAND
R2
R1
R3
THE OUTERMOST ORBIT ELECTRONS
ARE CALLED VALENCE ELECTRON
EDGE OF NUCLEUS
VALANCE BAND
CONDUCTION BAND(FREE ELECTRONS)
FORBIDDEN ENERGY
GAP

13. CONDUCTORS
FREE ELECTRONS
EDGE OF NUCLEUS
VALANCE BAND
{OUTERMOST ORBIT ELECTRONS)
CONDUCTION BAND
(FREE ELECTRONS)

14. CONDUCTOR
WIRE

15. INSULATOR
NO FREE ELECTRONS
EMPTY
VALANCE BAND
{OUTERMOST ORBIT ELECTRONS)
CONDUCTION BAND
(FREE ELECTRONS)
FORBIDDEN ENERGY GAP
EDGE OF NUCLEUS
FILLED

16. SEMICONDUCTOR
NO FREE ELECTRONS
ALMOST EMPTY
VALANCE BAND
{OUTERMOST ORBIT ELECTRONS)
CONDUCTION BAND
(FREE ELECTRONS)
FORBIDDEN ENERGY GAP
EDGE OF NUCLEUS
ALMOST FILLED

17. ELECTRICAL CONDUCTIVITY DIFFERS
CONDUCTOR INSULATOR SEMICONDUCTOR

18. THANK YOU FOR
LISTENING!!!