A shunt-connected a DC motor has zero rotational losses and R A = 0. Assume that R A and R adj is constant [except in part (d)] and that is directly proportion to feild current. For VT= 200 V and P out = 2 hp. The speed is 1200 rpm. What is the effect on IA and speed if :
a) The load torque doubles.
b) The load power doubles.
c) VT is changed to 100V and P out remains constant
d) RA + Radj is doubled in value and P out remains constant?