Un-Answered Questions { Electrical Engineering }

On 400 amp factory load how kvarh capacitors provide

732


What is shunt voltage and u v voltage witch one best

749


A 10 MVA, 66KV, 50Hz, Y-connected 3-phase alternator has synchronous reactance of 0.635 Ù. It is working at full load at 0.8 lagging p.f. condition. Find torque angle, neglect armature resistance.

1042


With a phasor diagram show the effect of increasing the field current of a generator supplying a constant real power and connected to a grid system.

883


Draw the wave shape of armature current in a generator subjected to a sudden three phase short- circuit at its terminals. Define various reactance of generator from this wave shape.

840





A 400 V, 50 Hz, Δ connected synchronous generator has a field reactance of 0.1 Ω and armature resistance of 0.015 Ω. At full load, the machine supplies 1200 A at 0.8 pf lagging. Under full-load conditions, the friction and windage losses are 40 KW and the core losses are 30 KW. What is the machine’s overall efficiency? Ignore any field circuit losses.

684


A generating system will have a total capacity of 300 MW. Find the probable forced outage when the capacity is supplied by two 150 MW units. The operating probability of all units is P=0.98 and forced outage probability rate Q =0.02 .

1236


A 500 V shunt motor runs at its normal speed of 250rpm when the armature current is 200A. The resistance of the armature is 0.12 Ω. Calculate the speed when a resistance is inserted in the field reducing the shunt field to 80% of normal value and the armature current is 100A.

995


What is meant by load angle of an alternator? Upon what factors does the load angle depend?

1891


How do the synchronizing lamps indicate the correctness of phase sequence between existing and incoming alternators?

864





What is industrial plc

720


How we can defined theecopper cable size if we know the aluminium cable size?

791


what is effect of length of air gap on performance of dc motor and generator?

701


How much ph is maintained of water electrolyte which is used in LRS for 1200 kw slipring induction motor ?

657


how to select fuse rating for a 3-phase motor ???

766