سوال ۲۷ کنکور ارشد مهندسی برق ۱۴۰۰

PASSAGE 3:

For millennia, people have harnessed the power of the wind to accomplish tasks. For example, merchants once relied on the wind to sail the world. Also, old windmills, once used to mill cereals, are an iconic part of Holland's landscape. With our lives centered around electricity, modern scientists have found innovative ways to convert the kinetic energy from the wind into electric power.

Today, around the world, the wind-electric turbine is becoming as iconic as the Dutch windmill. A wind turbine typically consists of a large, three-bladed propeller, called a rotor, atop a tower that's high enough that nothing blocks it from the wind. The turbine has a drive train similar to a car's engine that includes an electric generator. The electricity generated gets added to the electric grid, <u>which</u> powers hundreds of homes and businesses in a geographic location.

One small wind turbine can power a single home or small business. These smaller versions have rotors between 8 and 25 feet (2.4 and 7.6 meters) in diameter and can stand up to 30 feet (9.1 meters) in the air. Wind farms are becoming increasingly common in large open spaces. You can see some of these farms during a drive or flight through the country, with thousands of giant white wind turbines stretching across hillsides as far as the eye can see.

What is the main function of the second paragraph?