Open circuited armature coil of a D.C. machine is________?
Aindicated by a spark completely around the commutator
Bnone of the above
Cboth A. and (b)
Didentified by the scarring of the commutator segment to which open circuited coil is connected
Correct answer
C. both A. and (b)
Explanation
The correct answer is both A. and (b).