Is there a relationship for calculating the number of samples ($N$) that must be used in order to minimize spectral leakage of a discrete time signal.
For example, given a signal
$$x[n] = \sin(2\pi f_0 n T)$$
and $f_0 = 5, T = 0.02, n = 0, \ldots, N-1$, and no information regarding the sampling frequency, how do we choose the value for $N$?
I saw somewhere that $N$ would be equivalent to the sampling frequency, yet again, assuming that isn't available, is there a way of obtaining $N$?