Electrical Machines Commutator in DC generator is used for reduce losses convert AC armature current in to DC increase efficiency collecting of current reduce losses convert AC armature current in to DC increase efficiency collecting of current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will increase by 5 %. depend on other factors. remain unchanged. reduce by 5 %. increase by 5 %. depend on other factors. remain unchanged. reduce by 5 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor copper loss? 60W 80W 100W 40W 60W 80W 100W 40W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1200 1203 1000 1080 1200 1203 1000 1080 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. What is the operating frequency, if the load is 600 MW? 48.5 Hz 50 Hz 48 Hz 45 HZ 48.5 Hz 50 Hz 48 Hz 45 HZ ANSWER DOWNLOAD EXAMIANS APP
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