Which one of the following can not be used for measurement of time ?
D
Shadow of an object during the day
Correct option is D. Blinking of eyes
"A leaking tap" is the answer because we cannot estimate when will the drop fall.
where as
⇒ simple pendulum shows time by its to and fro motion.
⇒ in olden days the time is estimated by the shadow of an object
⇒ blinking of eyes is rarely seen which blinks by time unless by reflex actions