Answer:
The pendulum with the greatest frequency is one with short length.
Step-by-step explanation:
A simple pendulum is a device which consists of mass m hanging from the string of length L attached to the some point.When displaced and released its swings back and forth with periodic motion.
The frequency of simple pendulum is given by
f =

where T is the time period.
f =1/2π√g/l
where , l is the length of pendulum
g is acceleration due to gravity.
The frequency of simple pendulum is defined as how much time or the distance covered by the bob in one second
From the given equation we can find that the frequency of the simple pendulum is inversely proportional to square root of length.Hence the frequency will be maximum if the length of the bob is short.