DC Motors Which D.C. motor is generally preferred for cranes and hoists? Shunt motor Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor Series motor Differentially compounded motor Cumulatively compounded motor ANSWER DOWNLOAD EXAMIANS APP
DC Motors In a dc motor if the back emf is absent Motor will not run at all Motor will run at very slow speed Motor will run at very high speed Motor will burn Motor will not run at all Motor will run at very slow speed Motor will run at very high speed Motor will burn ANSWER DOWNLOAD EXAMIANS APP
DC Motors If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens Motor will run at very slow speed This will make armature to take heavy current, possibly burning it This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses Nothing will happen to the motor Motor will run at very slow speed This will make armature to take heavy current, possibly burning it This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses Nothing will happen to the motor ANSWER DOWNLOAD EXAMIANS APP
DC Motors The starting resistance of a DC motor is generally Low 1000 Ω Around 500 Ω Infinitely large Low 1000 Ω Around 500 Ω Infinitely large ANSWER DOWNLOAD EXAMIANS APP
DC Motors If conditions for maximum power for a dc motor are established, the efficiency of the motor will be 60 to 70 % 80 to 90 % 100 % Less than 50% 60 to 70 % 80 to 90 % 100 % Less than 50% ANSWER DOWNLOAD EXAMIANS APP
DC Motors Usually wide and sensitive speed control is desired in case of Elevators Centrifugal pumps Steel rolling mills Colliery winders Elevators Centrifugal pumps Steel rolling mills Colliery winders ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS