Electrical Machines Armature resistance control method is used for the _______ ? None of these both 1 and 2 below rated speed above rated speed None of these both 1 and 2 below rated speed above rated speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will both decrease both increase decrease and increase respectively increase and decrease respectively both decrease both increase decrease and increase respectively increase and decrease respectively ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Ns = 120f / p × ( 1 - s ). Nr = 120f / p × (1-s). None of these Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). Nr = 120f / p × (1-s). None of these Ns = 120f /p × ( 1 - r). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1, 2 and 4 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to withstand All of these any unbalanced magnetic pull on the armature core. bending moment due to weight of the armature. twisting strains due to transmission of torque. All of these any unbalanced magnetic pull on the armature core. bending moment due to weight of the armature. twisting strains due to transmission of torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field divertor method of speed control of a DC series motor gives speed above rated one due to reduction of None of above. Line current. Armature current. Field current. None of above. Line current. Armature current. Field current. ANSWER DOWNLOAD EXAMIANS APP
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