SSC JE Electrical 2019 with solution SET-1 A synchronous motor runs at 600rpm, which of the following case is true? P= 12, f = 50 Hz P = 8, f = 50 Hz P = 12, f = 60 Hz P = 10, f = 60 Hz P= 12, f = 50 Hz P = 8, f = 50 Hz P = 12, f = 60 Hz P = 10, f = 60 Hz ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Synchronous speed NS = 120f/PWhenP = 12 & F = 60 then Ns = ?NS = 120f/P = (120 × 60)/12 = 600 RPM
SSC JE Electrical 2019 with solution SET-1 Which of the following losses is together called iron losses? Hysteresis loss and frictional loss Hysteresis loss and copper loss Eddy current loss and hysteresis loss Eddy current loss and frictional loss Hysteresis loss and frictional loss Hysteresis loss and copper loss Eddy current loss and hysteresis loss Eddy current loss and frictional loss ANSWER DOWNLOAD EXAMIANS APP
SSC JE Electrical 2019 with solution SET-1 Which of the following is the function of the moderator in a nuclear reactor? Stopping chain reaction Starting chain reaction Controlling chain reaction To slow down the fast-moving electron Stopping chain reaction Starting chain reaction Controlling chain reaction To slow down the fast-moving electron ANSWER DOWNLOAD EXAMIANS APP
SSC JE Electrical 2019 with solution SET-1 What is the reason behind using a centrifugal switch in a single-phase induction motor? To out in the capacitor during running conditions To cut-off the starting winding at an appropriate instant To protect the motor from overloading To improve the starting performance of the motor To out in the capacitor during running conditions To cut-off the starting winding at an appropriate instant To protect the motor from overloading To improve the starting performance of the motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The centrifugal switch is used to disconnect the starting winding of the motor once the motor approaches its normal operating speed i.e 50% – 70% speed.
SSC JE Electrical 2019 with solution SET-1 ______starting method CANNOT be used for starting a 3-phase squirrel cage induction motor Auto-transformer Direct-on-line Star-delta Rotor-resistance Auto-transformer Direct-on-line Star-delta Rotor-resistance ANSWER DOWNLOAD EXAMIANS APP
SSC JE Electrical 2019 with solution SET-1 The Thevenin’s resistance as seen through the terminals A and B is: 5 Ω 8 Ω 6 Ω 4 Ω 5 Ω 8 Ω 6 Ω 4 Ω ANSWER DOWNLOAD EXAMIANS APP
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