Which of the following are true about wind farms? A. They are often installed…

Concept. A wind farm is a cluster of wind turbines built at one site so that the kinetic energy of moving air can be converted into electrical energy. Wind belongs to the renewable class of resources: the atmospheric circulation that carries it is regenerated continuously by solar heating of the earth’s surface and the planet’s rotation, so drawing energy from it never draws down a finite stock — unlike coal, petroleum or natural gas, which exist as fixed deposits and are consumed as they are burnt. Two further properties follow from the machine itself: every rotor leaves a slowed, turbulent wake downwind of it, and a rotating rotor together with its drivetrain radiates sound.

Application. Test each listed statement against those properties.

• Statement A — row installation: because a rotor’s wake starves the machine behind it, turbines are laid out in spaced arrays, typically about 5–10 rotor diameters apart along the prevailing wind and closer across it. Rows are therefore the standard site layout, so the statement holds.

• Statement B — noise pollution: blades generate aerodynamic swish as they cut the air and the gearbox and generator in the nacelle add mechanical sound. This is why siting rules prescribe minimum setback distances from dwellings, so the statement holds.

• Statement C — land or offshore: wind farms are built both onshore and in shallow coastal waters, where sea winds are stronger and steadier and there are no neighbours to disturb. The statement holds.

• Statement D — non-renewable: wind is replenished continuously by solar-driven atmospheric circulation, which is the defining test of a renewable resource. Calling it non-renewable inverts that classification, so this statement does not hold.

• Statement E — grid contribution: the turbines feed a collector network, the voltage is stepped up at the farm substation and the power is exported over transmission lines into the public grid; that is the entire commercial purpose of a utility-scale farm. The statement holds.

Cross-check. One test settles the whole item: every combination offered except A, B, C and E Only carries statement D, and D contradicts the defining property of wind as a continuously replenished resource. Eliminating every set that contains D leaves exactly one survivor, which independently agrees with the statement-by-statement check above.

Result. The true statements are A, B, C and E, so the correct combination is A, B, C and E Only.