## DC Generators

**Important terms and formulae of DC Generators, ****EMF induced in a DC Generator is given by the equation, ****Types of DC Generators, ****Important terms of DC Generators, Separately Excited DC Generators**, **Series DC generators, ****Shunt DC generators, ****Compound DC generators – ****Long Shunt Compound generator, ****Short Shunt Compound generator**

## Topic

## DC Generators Problems

- A shunt generator has 4 poles lap wound armature having 24 slots with 10 conductors per slot. If the flux per pole is 0.04 wb and the speed is 1500 rpm, Calculate the EMF generated in the armature. What would be the generated EMF if the winding is wave connected?
- A 4 pole DC shunt generator with lap connected armature has field and armature resistance of 50Ω and 0.1Ω respectively, If the generator supplies sixty 100V, 40W lamps, calculate the total armature current the current in each armature conductor and the generated EMF. Take 1V per brush as contact drop.
- A 4-pole armature of DC Generator has 624 lap connected conductors and is driven at 1200 rpm. Calculate the useful flux per pole required to generate an EMF of 250 V.
- A shunt wound DC generator delivers 496 A at 440 V to the load with shunt resistance of 110 ohm and armature resistance of 0.02ohm. Calculate the EMF induced in the armature.
- The EMF generated in the armature of a shunt generator is 625 V, when delivering its full current of 400 A to an external circuit if the field current is 6 A and armature resistance of0.06ohm, what is the terminal voltage?
- A shunt generator delivers 50 KW at 250 V and runs at 400 rpm. Armature resistance and field resistance are 0.02 ohm and 50 ohm respectively. Calculate the speed of the machine running as a shunt motor and taking 50 KW input at 250 V. Allow 1 V per brush for contact drop.
- An 8-pole lap connected armature has 960 conductors a flux of 40 mwb per pole and speed of 400 rpm. Calculate the EMF generated if the armature were wave connected, at what speed must it be driven to generate 400 V.
- A 4-pole lap wound DC shunt generator delivers 200 A at terminal voltage of 250 V. It has a field and armature resistance of 50 Ω and 0.05 Ω respectively. Neglecting brush drop, Determine (i) Armature current (ii) Current per parallel path (iii) EMF generated (iv) Power delivered.
- A 30 KW, 300 V DC shunt generator has a armature and field resistance of 0.05 Ω and 100 Ω respectively. Calculate the power delivered by the armature when it delivers full output power.
- A 4-pole generator with wave wound armature has 51 slots each having 24 conductors rotate to give an induced EMF of 220 V. What will be the voltage developed if the winding is lap and the armature rotates at the same speed?
- A shunt wound DC generator delivers 496 A at 440 V to load. The resistance of the shunt field coil is 110 Ω and that of armature winding is 0.02 Ω. Calculate the EMF induced in the coil armature.
- A shunt generator running at 500 rpm delivers 50 KW at 200 V. The armature and field resistances are 0.02 Ω and 40 Ω respectively. Calculate generated EMF if brush drop of 1 V per brush.
- An 8-pole DC generator has 500 armature conductors, and useful flux per pole of 0.065 wb. What will be the EMF generated if it is lap connected and runs at 1000 rpm. At what speed it must be driven to produce the same EMF if it is wave connected.
- An 8-pole lap connected armature has 40 slots with 12 conductors per slot, generate a voltage of 500 V. Determine the speed at which it is running if the flux per pole is 50 mwb.
- A 4-pole 1500 rpm DC generator has lap wound armature having 24 slots with 10 conductors per slot. If the flux per pole is 0.04 wb, calculate the EMF generated in the armature. What would be the generated EMF if the winding is wave connected.