Its a somewhat effeincent linear regulator. Vec@2A = 5.63 - 5.01 = 0.62v
Pbjt = IV = 2*0.62= 1.24 W
Pload = 2*5.01 = 10 W
Pbjt + Pload =~Pin
100*(Pout/Pin) = 100* (10 / 11.24) = 89% eff
89% @ 2A effeincent sound about right?
Efficency is inversely proportional to the load resistance. In other words, if one goes up, the other goes down.