The question asks about the type of current that changes both its magnitude and direction at definite intervals. Let's analyze the given options:

1. Leakage current: This is an unwanted flow of electrical current that escapes the intended path in an electric circuit. It does not change direction at regular intervals and is generally undesired.
2. Alternating current: This is a type of electrical current that periodically reverses direction and changes its magnitude over time. The most common form of alternating current is the sine wave, which continually oscillates between positive and negative cycles, typically used in household power supplies.
3. Direct current: In this type of current, electric charge flows in one direction only. It does not change direction or magnitude at regular intervals, as it remains constant.
4. Static current: This is not a commonly used term in electrical engineering. It generally refers to static electricity, which is a stationary electric charge typically produced by friction. This does not concern regular intervals of changing magnitude or direction.

Based on the analysis:

• The correct answer is Alternating current as it regularly changes both its magnitude and direction at definite intervals, fulfilling the condition specified in the question.

Therefore, the answer is correct and aligns with the definition of alternating current.