[" State the principle behind electric generator."],[" The output frequency of wind turbine is "50Hz" .What is meant by this statement? "],[" Why do you think Muppandal is at an advantageous position for this project? "]

Answer the following questions: The frequency of vibration of a string is 100Hz. What do you understand by the statement?

The electrical generators used for wind turbines on sites where there is an access to the seasonal monsoon winds, produce an output AC of 240 V and a frequency of 50 Hz even when the wind speed is fluctuating. A transformer may be required to increase or decrease the voltage so it is compatible with the end usage, distribution or transmission voltage, depending on the type of interconnection. The output frequency of wind turbine is 50 Hz. What is meant by this statement?

What do you mean by electric fuse ? State its working principle.

Dinesh is a student of 10th standard. He went to a remote area of Rajasthan for trekking with his friends. Dinesh found that it was a sparsely inhabited area. He was surprised to know that there was still no electricity in this area. The children also had to study with kerosene lamps at night. The village farmers used diesel to run irrigation pumps. Actually, there were no power transmission lines which could bring electricity to this remote area. Dinesh was really disturbed by the living conditions of the people in this part of Rajasthan. One day Dinesh gathered all the people of village in the village school. He told them that if they put pressure on their area MLAs and MP for making available the required funds, then he could tell them about the devices to light up their homes and streets at night, play radio and television and also run irrigation pumps with electricity without there being power transmission lines. All the people agreed and Dinesh described them the devices to get electricity in their area in detail. The village people were very happy to know this and soon they got electricity in their area. (a) What was the device described by Dinesh to the village people to obtain electricity locally ? (b) What source of energy is made use of in this device to obtain electricity ? (c) Why do you think this device is more appropriate for an area like Rajasthan ? (d) What is the name of the single unit of this device ? What values are shown by Dinesh in this incident ?