In this one word substitution question, select the single word that best expresses the phrase "the tendency to recur at intervals".

Introduction / Context:

This question belongs to the topic of one word substitutions in English. You are given a descriptive phrase, "the tendency to recur at intervals", and asked to select a single word that captures the same idea. Such questions are common in competitive exams because they test both vocabulary depth and precision. The phrase clearly relates to something happening repeatedly after fixed or roughly regular time gaps.

Given Data / Assumptions:

• The phrase is "the tendency to recur at intervals".
• The options are rotation, wheel, sequence, and periodicity.
• The correct answer should denote recurring events in time rather than physical objects or loosely related concepts.
• The usage is general and can apply to phenomena in nature, science, or daily life.

Concept / Approach:

The key words in the phrase are "recur" and "intervals". In English, "periodic" describes something that happens at regular intervals, and the noun "periodicity" refers to the quality or property of being periodic. Thus "periodicity" captures exactly the tendency of something to recur after a fixed period. "Rotation" usually refers to spinning or turning, especially of an object around an axis. "Wheel" is a physical object, not a property of recurrence. "Sequence" refers to order or arrangement, not to repetition at intervals. Therefore, the concept we need is clearly linked to the adjective "periodic".

Step-by-Step Solution:

Verification / Alternative check:

Check typical uses of each candidate word. In physics and mathematics, we talk about the "periodicity" of a wave or the periodicity of an economic cycle, meaning the pattern of repetition over time. We do not usually speak of the "wheel" or "sequence" of a disease to describe how it recurs. While you may say that Earth completes a rotation every day, the noun "rotation" in isolation does not cleanly stand for "tendency to recur". The fact that textbooks and scientific descriptions regularly use "periodicity" for repeated cycles confirms that it is the intended answer.

Why Other Options Are Wrong:

"Rotation" emphasises movement around an axis and is too specific, missing the general notion of recurrence at intervals. "Wheel" is simply an object used for movement and has no meaning related to recurring events. "Sequence" refers to ordered arrangement, such as in a number sequence, but not necessarily repeated patterns. None of these three words inherently convey the idea of something repeatedly happening with a fixed or regular time gap.

Common Pitfalls:

Some candidates are tempted by "rotation" because rotating things do repeat their position, so they loosely associate it with recurrence. Others may confuse "sequence" with repeated patterns. The safest strategy is to ask yourself which word is used in definitions and explanations when describing cycles or repeated phenomena. That word is "periodicity", which is directly derived from "periodic".

Final Answer:

The one word substitution for "the tendency to recur at intervals" is periodicity.