During washing of filter at the end of constant pressure filtration, the rate of washing equals the rate of filtration%!

When half the filtrate has been obtained

At the end of filtration, but decreases with time subsequently

During washing of filter at the end of constant pressure filtration, t

1.	During washing of filter at the end of constant pressure filtration, the rate of washing equals the rate of filtration%!
A.	At time zero
B.	At the end of filtration
C.	When half the filtrate has been obtained
D.	At the end of filtration, but decreases with time subsequently
Answer» C. When half the filtrate has been obtained