What is the difference between AC and DC power.

a. AC power flows in one direction only, while DC power flows in both directions.
b. AC power changes direction periodically, while DC power flows in one direction only.
c. AC power is used for high-voltage applications, while DC power is used for low-voltage applications.
d. AC power is more efficient than DC power.
Answer: b. AC power changes direction periodically, while DC power flows in one direction only.