The frequency of direct current is ________ A. Zero B. 50 HZ C. 60 HZ D. 100 HZ

The frequency of direct current is zero. Direct current (DC) is a type of

electric current that flows in one direction only. It is produced by batteries, solar cells, and other sources that do not change polarity. The frequency of DC is zero because there is no change in the direction of the current.

Alternating current (AC) is a type of electric current that changes direction periodically. It is produced by generators and other sources that change polarity. The frequency of AC is the number of times per second that the current changes direction. The standard frequency for AC in most countries is 50 Hz or 60 Hz.

In conclusion, the frequency of direct current is zero.