Electrical Machines The heat transfer by convection in a transformer least depends on surface area. air velocity. color of the paint. temperature difference. surface area. air velocity. color of the paint. temperature difference. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1 and 2 1 and 3 1, 2 and 3 2 alone 1 and 2 1 and 3 1, 2 and 3 2 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 3.1 Ω 2 .1 Ω 1.8 9 Ω 1.79 Ω 3.1 Ω 2 .1 Ω 1.8 9 Ω 1.79 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the commutator pitch? Number of conductors spanned by one coil at the front end of the armature. Number of commutator segments between two successive coils. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the back end of the armature. Number of conductors spanned by one coil at the front end of the armature. Number of commutator segments between two successive coils. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the back end of the armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to equalizing coils. DC supply. external star-connected resistors. 3 - Φ AC supply. equalizing coils. DC supply. external star-connected resistors. 3 - Φ AC supply. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following winding is connected in series with armature winding of DC machine? Auxiliary winding. Commutating pole winding. Compensating winding. Both Compensating and Commutating pole winding. Auxiliary winding. Commutating pole winding. Compensating winding. Both Compensating and Commutating pole winding. ANSWER DOWNLOAD EXAMIANS APP
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