The load lifted would be a maximum when conditions are ideal. Since this set-up uses three strands of string, the load gets raised only through 1/3rd of the distance through which the effort moves.
Velocity ratio = Distance moved by the effort/Distance moved by the load
Under ideal condition, V.R. = M.A.
Hence, Ideal M.A. of the set-up = 3.
∴ Maximum load that can be lifted = Effort x 3 = 100 N x 3
= 3000 N.
Under actual conditions, M.A. = Load/Effort
= 2700 N/1000 N
Efficiency = M.A./V.R. = 2.7/3
= 0.9 = 90%.