Consider the principle that the torque in a rotating machine is proportional to peak of stator MMF(Fs), rotor MMF(Fr) an

[answerhappygod]

(i) δ is fixed in DC machine
(ii) Fs is fixed in DC shunt machine
(iii) δ is variable in induction machine
(iv) Fr is fixed in synchronous machne
(v) Fr is variable in DC machine
(vi) Fr is fixed in induction motor
(vii) resultant of Fs and Fr is fixed in synchronous motor
a) (i), (ii), (iii), (iv) and (vi)
b) (i), (ii), (iii), (v) and (vii)
c) (ii), (iii), (v), (vi) and (vii)
d) (i), (ii), (iv), (v) and (vii)