Subject Experts Solutions for Chapter: Chemical Effects of Electric Current, Exercise 3: TOUGH NUT

Will the size of the copper rod be affected in any way during the electroplating of iron with copper? 

Why does an LED require less electrical energy as compared to an electric bulb? 

Rani and her mother Sarojni were sitting outside in the verandah, talking about Rani's studies and career options. They saw some well-dressed people on the street, selling some items. Sarojni was intrigued and invited them to her house. These people told her that they were from a far-off state in India. They had come to Sarojni's state as a tourist but were robbed of all their money and documents. They only had one gold ring left, with a market rate of rupees sixty thousand, but they were willing to sell it for rupees twenty thousand as they were in urgent need of money. They showed the ring to Sarojni, who on examining saw that the ring was genuinely made of gold. On weighing the gold ring, Sarojni found that it would be worth rupees fifty-eight- to Sixty two thousand in the market. Sarojni wanted to buy the ring. She left the ring with Rani and went inside the home for fetching money. Looking at the ring, Rani remembered a process she had learned about in chapter Chemical Effects of electric Current of her science textbook. She took the ring and started rubbing it against a stone in her pocket. 
After rubbing it for some time, she took out the ring and saw that it was actually made of cheap metal with only a coating of gold. What is the process that Rani remembered?

Rani and her mother Sarojni were sitting outside in the verandah, talking about Rani's studies and career options. They saw some well-dressed people on the street, selling some items. Sarojni was intrigued and invited them to her house. These people told her that they were from a far-off state in India. They had come to Sarojni's state as a tourist but were robbed of all their money and documents. They only had one gold ring left, with a market rate of rupees sixty thousand, but they were willing to sell it for rupees twenty thousand as they were in urgent need of money. They showed the ring to Sarojni, who on examining saw that the ring was genuinely made of gold. On weighing the gold ring, Sarojni found that it would be worth rupees fifty eight- to Sixty two thousand in the market. Sarojni wanted to buy the ring. She left the ring with Rani and went inside the home for fetching money. Looking at the ring, Rani remembered a process she had learned about in chapter 14 of her science textbook. She took the ring and started rubbing it against a stone in her pocket. 
After rubbing it for some time, she took out the ring and saw that it was actually made of a cheap metal with only a coating of gold. Besides jewellery, list two items which are coated by precious metals?

Rani and her mother Sarojni were sitting outside in the verandah, talking about Rani's studies and career options. They saw some well-dressed people on the street, selling some items. Sarojni was intrigued and invited them to her house. These people told her that they were from a far-off state in India. They had come to Sarojni's state as a tourist but were robbed of all their money and documents. They only had one gold ring left, with a market rate of rupees sixty thousand but they were willing to sell it for rupees twenty thousand as they were in urgent need of money. They showed the ring to Sarojni, who on examining saw that the ring was genuinely made of gold. On weighing the gold ring, Sarojni found that it would be worth rupees fifty eight- to Sixty two thousand in the market. Sarojni wanted to buy the ring. She left the ring with Rani and went inside the home for fetching money. Looking at the ring, Rani remembered a process she had learned about in chapter 14 of her science textbook. She took the ring and started rubbing it against a stone in her pocket. 
After rubbing it for some time, she took out the ring and saw that it was actually made of a cheap metal with only a coating of gold. 

When do people try to cheat Others?

Jasmine's uncle works in an electroplating factory. One day Jasmine told his uncle that she read about electroplating in her science textbook and wanted to see the factory. Her uncle agreed to take her to the factory. Early next morning, Jasmine reached the factory with her uncle and saw all the workers, smartly dressed, coming into the factory. Inside the factory, she saw various electroplating processes going on. Jasmine asked her uncle about the risks of electroplating. Her uncle told her that nickel and chromium exposure causes poisoning and that there was also a high risk associated with disposal of the toxic waste.
Which quality of electricity is used in electroplating? 

Jasmine's uncle works in an electroplating factory. One day Jasmine told his uncle that she read about electroplating in her science textbook and wanted to see the factory. Her uncle agreed to take her to the factory. Early next morning, Jasmine reached the factory with her uncle and saw all the workers, smartly dressed, coming into the factory. Inside the factory, she saw various electroplating processes going on. Jasmine asked her uncle about the risks of electroplating. Her uncle told her that nickel and chromium exposure causes poisoning and that there was also a high risk associated with disposal of the toxic waste.
Name two more materials which are also used for electroplating. 

Jasmine's uncle works in an electroplating factory. One day Jasmine told his uncle that she read about electroplating in her science textbook and wanted to see the factory. Her uncle agreed to take her to the factory. Early next morning, Jasmine reached the factory with her uncle and saw all the workers, smartly dressed, coming into the factory. Inside the factory, she saw various electroplating processes going on. Jasmine asked her uncle about the risks of electroplating. Her uncle told her that nickel and chromium exposure causes poisoning and that there was also a high risk associated with disposal of the 
toxic waste.
How can we restrict the harmful effects of electroplating?