Electrical Machines In DC generators, the cause of rapid brush wear may be rough commutator surface. severe sparking. imperfect contact. any of above. rough commutator surface. severe sparking. imperfect contact. any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature in the polar axis. commutator in the inter polar axis. armature midway between poles. commutator in the polar axis. armature in the polar axis. commutator in the inter polar axis. armature midway between poles. commutator in the polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A delta/star transformer is connected in parallel to a star/delta transformer. The turn ratio former is x times latter, the x is √3 1/√3 3 1/3 √3 1/√3 3 1/3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the e.m.f. generated by a 4 pole lap connected DC Generator rotating at 1500 r.p.m.? Its flux per pole is 0.4 mWb and total no of armature conductors is 1000. 30 volts. 10 volts. 20 volts. 40 volts. 30 volts. 10 volts. 20 volts. 40 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be an integral multiple of number of rotor slots. either (B) or (C). unequal to number of rotor slots and skewed in shape. equal to number of rotor slots. an integral multiple of number of rotor slots. either (B) or (C). unequal to number of rotor slots and skewed in shape. equal to number of rotor slots. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors are preferred in lifts? DC series motors. DC shunt motors. DC compound motors. None of these DC series motors. DC shunt motors. DC compound motors. None of these ANSWER DOWNLOAD EXAMIANS APP