C. Short answer type questi
1. Write down a short note on electronics
2. How are the machines useful for farmers ?
3. How did the use of iron change the life of ea
4. How was copper metal discovered ?
5. Mention the main sources of power
D. Distinguish between the following.
1. Iron and Copper
2. Lifting machines and Construction machin
Answers
Answer:
1) Electronics deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes, integrated circuits, optoelectronics, and sensors, associated passive electrical components, and interconnection technologies.
2) Farm machinery, mechanical devices, including tractors and implements, used in farming to save labour. Farm machines include a great variety of devices with a wide range of complexity: from simple hand-held implements used since prehistoric times to the complex harvesters of modern mechanized agriculture.
3) After a few thousand years, man discovered iron, which was stronger than copper. From iron, he developed a variety of tools and weapons such as axes, ploughs, sickles, shovels, spears, etc. Now he could cut trees, till the land and kill big animals easily. He made stronger and bigger wheels for the carts.
4) The discovery of copper dates from prehistoric times. There are reports of copper beads dating back to 9000BC found in Iraq. Methods for refining copper from its ores were discovered around 5000BC and a 1000 or so years later it was being used in pottery in North Africa.
5) Legitimate Power.
Reward Power.
Coercive Power.
Referent Power.
Expert Power.
Cultivate Your Own Powers.
D (a) Iron (III) chloride solution
When NaOH solution is added a dirty green precipitate of iron (III) hydroxide is formed.
Copper chloride solution
When NaOH solution is added a bluish precipitate of copper (II) hydroxide is formed.
b) I don't know the second part.
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