Physics for IGCSE & O level - Magnets And Currents (Section 5 - No. 3)
Which of the following are reasons why a.c. is used for the mains?
It can be generated more efficiently than 'one-way' direct current (d.c.)
It is more effective
It can be stepped up and down using transformers
It can be used for high voltages
Vysvětlení
A.C. can be generated more efficiently and stepped up/down via transformers.