Sleep-wake cycle if external cue is removed will be which of the following?

Circadian clocks keep running even when the environmental cues (changes in light and dark) are removed, but the period of this free-running rhythm is generally a little less or a little more than 24 hours. More frequent is more than 24 hours. Ref: Chest Medicine: Essentials of Pulmonary and Critical Care Medicine edited by Ronald B. George, Richard W. Light, Michael A. Matthay, Richard A. Matthay, 2010, Page 461. 2. Psychiatric Mental Health Nursing By B. T. Basavanthappa, 2007, Page 141