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 Σ0 baryon, composed of the quark combination uds, is produced through the strong interaction between a π+ meson and a neutron. π+ + n →Σ0 + X What is the quark composition of X?
Describe an experiment, using a pendulum, which can be conducted to investigate g, acceleration due to gravity.
a solar cell of area 2m^2 has maximum a power output per unit area of 20W/m^2 . if four solar cells are used together at once, how much energy is release in 2 mins at max power output?
Define Newtons law of Gravitation (in words or an equation).