How much noise we can apply in a system so that system keep remain in \alpha-homomorphic encryption. Otherwise after adding extra noise or increasing parameter values it will destroy the scheme.
Where \alpha belongs to {Somewhat, Partial, Leveled}.
In short what is the percentage handled by alpha.
Can you share any resource ?

The answer depends on the scheme and performed computations (the â€ścircuitâ€ť). For instance, in BGV/BFV/CKKS the highest noise is incurred for multiplications. The multiplicative depth determines how many multiplications can be performed in a series.