Electrical Machines If field current is decreased in shunt dc motor, the speed of the motor None of these increases. remains same. decreases. None of these increases. remains same. decreases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pair of pole pairs, Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance? PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4Sp² PZL/4Sa² PZL/ 4Sa PZL/4S PZL/4Sp² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two generators G1 and G2 are to be operated in parallel to deliver a total current of 60 A. Generator one has a terminal voltage of 280 V on no load and 240 V when supplying 40 A current. Similarly the second generator has a voltage of 300 V when on no load and 240 V when supplying of 50 A of current. The output voltage of each generator will be 240 V. 271.7 V. 238.2 V. 256.4 V. 240 V. 271.7 V. 238.2 V. 256.4 V. 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 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable moisture content of power transformer insulating oil is generally taken as 45 ppm. 20 ppm. 25 ppm. 35 ppm. 45 ppm. 20 ppm. 25 ppm. 35 ppm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat transfer by convection in a transformer least depends on temperature difference. color of the paint. surface area. air velocity. temperature difference. color of the paint. surface area. air velocity. ANSWER DOWNLOAD EXAMIANS APP