A 6 pole, 12 kW, 240 V DC machine is wave connected. If this machine is now lap connected, all things remaining the same, calculated its power ratings (in kW).
The emf induced in each coil side of a coil is 10 V and the coil sides lies under opposite poles. The induced emf in them is – (in V)
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How many segments will be there in for the commutator of a 8 pole dc machine having a double layered simple wave wound armature with 86 slots?
In an 8 pole dc machine, 60 mechanical degrees correspond to how much electrical degrees?
A DC shunt generator delivers 50 A ot terminal voltage of 230 V. The armature and the shunt field resistance are 0.01 Ω and 45 Ω respectively. The stray losses are 400 W. The percentage efficiency of DC generator is _________.
A 4 pole dc generator has 1200 armature conductors and generates 250 V on open circuit running at a speed of 500 rpm. The diameter of the pole shoe circle is 0.35 m and the ration of pole arc to pole pitch is 0.7 while the length of the shoe is 0.2 m. Find the mean flux density in Tesla in the air gap. Assume lap winding in armature
A DC machine is operating as a generator and supplying 8 kW at terminal voltage of 300 V. After a while, it is used as a motor with terminal voltage and armature current remaining same. If the flux per pole is increased by 25% when shifting from generator to motor, what was the change in the speed while doing so, given that the armature resistance is 0.5 Ω ?
A 6 pole dc generator has 32 slots and 12 conductors per slot. The useful flex per pole is 50 mwb and speed is 1000 rpm. The generator emf is for the lap wound and wave wound respectively
A separately excited DC generator when running at 1500 rpm, supplies 200 A at 150 V. what will be the load current if speed drops to 1000 rpm. The resistance of armature is 0.25 Ω and voltage drop due to brush contact is 2 V
A 2pole DC shunt generator charges a 100 V battery of negligible internal resistance. The armature of the machine is made up of 1000 conductors each of 2 mΩ resistance. The charging currents are found to be 10 A and 20 A for generator speed 1055 and 1105 rpm respectively. Find the fieldcircuit resistance (in Ω).
24 docs263 tests

24 docs263 tests
