Explain why a transformer is used in electrical power lines.
Power stations use step-down transformers to decrease the voltage of the electrical output. The power lines have a constant resistance (say, R Ohms) which means there is a power loss across the lines given by P = IV. By using Ohm's law (V = IR), we can obtain the formula P = V^2 / R which shows that the power loss goes as the square of the voltage. By using a step down transformer, we can minimize the power loss that occurs during transmission.
ZM
Related Physics A Level answers
All answers ▸The tip of each prong of a tuning fork emitting a note of 320Hz vibrates in SHM with an amplitude of 0.50mm. What is the speed of each tip when its displacement is zero?
what would be the mass required to keep an object with a mass of 250kg orbiting at a constant distance of 100km with a linear velocity of 100m/s?
what is the scape velocity?
A supertanker of mass 4.0 × 10^8 kg, cruising at an initial speed of 4.5 m s^(–1), takes one hour to come to rest. Assume the force slowing down the tanker is constant.