ee105 basic electrical engineering

1. 9EE105.41 1
Name : G. Snehalatha
Designation : Lecturer
Branch : Electrical & Electronics Engineering
Institute : Govt. Polytechnic, Mahabubnagar
Year/Semester : I Year
Subject : Basic Electrical Engineering
Subject Code : EE105
Topic : Conducting Materials
Duration : 50 minutes
Sub Topic : Tungsten
Teaching Aids : PPT, Animation, Diagrams
Revised by : A.K.Srikanth, L/EEE, Q.Q.GPT, HYD

2. 9EE105.41 2
• Properties of Nichrome
• Applications of Nichrome
2
Recap
In the previous class we have studied about

3. 9EE105.41 3
• Understand the Properties of Tungsten
• Understand the Applications of Tungsten
On completion of this period , you would be able to
3
Objectives

4. 9EE105.41 4
What is the filament used for the
following Bulbs ?
• Tungsten (High resistivity material )
4

5. 9EE105.41 5
Tungsten
• Very high tensile strength in its thinnest form
• Can be drawn into very thin wires (ductile)
• Highest melting point amongst all metals
5

6. 9EE105.41 6
• Resistivity is twice that of Aluminium
Properties of Tungsten
• Hard metal
• Grey in colour
6
• Melting point is 33000 C
• Exhibit excellent magnetic properties.

7. 9EE105.41 7
• Resistivity is 5.46 µΩ-cm
• Working temperature is 2000 0 C
• Oxidizes very quickly in the presence of oxygen
• Does not become brittle at high temperatures
7
• Can easily alloy with steel called Tungsten steel
- it is a magnetic material of top quality
Properties of Tungsten
Contd..

8. 9EE105.41 8
Applications of Tungsten
• Used in Incandescent lamps as filaments
8

9. 9EE105.41 9
• Used in Halogen lamps as filament
9
Halozen lamp Halozen lamp
Applications of Tungsten
Contd..

10. 9EE105.41 10
• Used as filament in fluorescent lamps
10
Applications of Tungsten
Contd..

11. 9EE105.41 11
• Tungsten is a very hard metal and is one of the
standard resistance materials
• Can be drawn into very thin wires
• It is used as filament in Incandescent
lamps & Halogen lamps,
11
Summary
In this period we have discussed about

12. 9EE105.41 12
1. Melting temperature of Tungsten is
a) 13000 C
b) 14000 C
c) 33000 C
d) None of the above
12
Quiz

13. 9EE105.41 13
a) Less than Aluminium
b) More than Aluminium
c) Twice that of Aluminium
d) None of the above
2. Resistivity of Tungsten is
13
Quiz

14. 9EE105.41 14
1. State the properties of Tungsten
2. State the applications of Tungsten
14
Frequently Asked Questions

15. 9EE105.41 15
In the next class we will discuss about
Next Class topic
• Understand the Properties of Platinum.
• Understand the Applications of Platinum.

16. 9EE105.41 16
The will to win, the desire to
succeed, the urge to reach your
full potential... these are the
keys that will unlock the door to
personal excellence.
Eddie Robinson