Final answer:
The component in the electrical grid that increases the voltage of electric current for long distance transmission is a step-up transformer.
Step-by-step explanation:
In the electrical grid, the component that performs the function of increasing the voltage of electric current for long distance transmission is a step-up transformer. When power is generated at a power plant, it is initially at a lower voltage. The step-up transformer increases the voltage to thousands of volts, allowing for more efficient transmission over long distances.
By transmitting power at high voltage, the current is decreased which helps minimize the losses due to resistive heating. This is known as Joule losses.
For example, voltages ranging from 120 to 700 kV are used for long distance power transmission. The step-up transformer at the power plant increases the voltage to these levels before it is sent through transmission lines.