Engineering Question

. D.C. machines designed with a large value of air gap length have A.worst, ventilation B.poor ventilation C.better ventilation D.none of the above 2. _________ electromagnets generally function as holding magnets. A.Tractive B.Portative C.Either of the above D.None of the above 3. By which of the following methods motor rating for variable load drives can be determined ? A.Method of average losses B.Equivalent current method C.Equivalent torque method D.Equivalent power method E.All of the above 4. In direct cooled system using hydrogen both stator and rotor conductors are made A.solid B.hollow C.perforated D.any ofthe above 5. On which of the following variables heat convected depends ? A.Power density B.Temperature difference between heated surface and coolant C.Thermal resistivity, density, specific heat D.Gravitational constant E.All of the above 6. An instrument transformer is used to extend the range of A.induction instrument B.electrostatic instrument C.moving coil instrument D.any of the above 7. The value of exciting or magnetizing current depends upon which of the following factors ? A.Total m.m.f. required B.The number of turns in the exciting winding C.The way in which the winding is distributed D.All of the above 8. The voltage control in electric supply networks in required on account of which of the following reasons ? A.Adjustment of voltage at consumers premises within statutory limits B.Control of active and reactive power C.Adjustment of short period daily and seasonal voltage variations in accordance with variations of load D.All of the above 9. The function of shunt in an ammeter is to A.by pass the current B.increase the sensitivity of the ammeter C.increase the resistance of ammeter D.none of the above 10. A phase shifting transformer is used in conjunction with A.D.C. potentiometer B.Drysdale potentiometer C.co-ordinate potentiometer D.Crompton potentiometer