A shunt-joined a DC motor consists of zero rotational losses and R A = 0. Suppose that R A and R adj is directly proportion to field current. For VT= 200 V and P out = 2 hp. The speed is 1200 rpm. Determine the effect on IA and speed when:
i) The load torque twice.
ii) The load power twice.
iii) VT is changed to 100V and P out remains constant.
iv) RA + Radj is twice in value and P out remains constant?