EE - DC Machines

How many parallel paths are there in the triplex lap wound armature of a 4 pole, dc generator?

A 4 pole, dc generator with duplex lap wound armature current of 5A per conductor. What is the total armature current in amperes?

A 4 pole, dc generator has 400 conductors in its simplex wave wound armature. With a flux of 0.02 Wb per pole, the voltage generated by the armature is 213.33 V. Find the generator speed in rpm.

When a dc generator is ran at 1080 rpm, the generated emf is 207 V. Find the generated emf in volts if the speed increased to 1200 rpm while the flux is kept constant.

The no load voltage of a 50-kW, 220 volts, shunt generator in the FEU laboratory is 232 volts and rated load voltage is 220 volts. The armature resistance including brushes is 0.026 ohms and the resistance of the shunt field resistance is 52 ohms. What is the induced electromagnetic force at rated load?

A 230-volt shunt generator has an armature circuit resistance of 0.05 ohm and shunt field resistance of 57.5 ohms. When the generator operates at rated voltage, it has a total core and mechanical losses of 1880 W. At what load does the generator operate so as to achieve maximum efficiency?

A 30 kW series generator has an efficiency of 88 percent when operating at rated load. If the stray power loss is 15% of the full load losses, calculate the maximum efficiency of the generator. Assume that the stray power loss is constant and the other losses varies as the square of the load.

Two dc shunt generators 1 and 2 are connected in parallel supplying 120 A to a common load. Generator 1 has no-load voltage of 450 V and full load voltage of 375 V at 80 A; while generator 2 has no-load voltage of 475 V and full load voltage of 375 V at 100 A. Assuming the external characteristic curves of both machines to be straight lines, find the current delivered by generator 2 in amperes.

A 4400v, 60 HZ transformer has a core loss of 840 watts, of which 1/3 is eddy current loss. What is the core loss when the transformer is connected to a 4600 v, 50 HZ source?

Two compound generators are operated in parallel. If generator A has a series field resistance of 0.0015 ohm and is adjusted to take 30% of the line load while generator B with a series field resistance of 0.001 ohm takes the remainder of the load, what is the current flow in the equalizer, when the load is 230-kW at 230-volts.

A short shunt compound generator has an armature, series, and field resistances of 0.04 ohm, 0.03 ohm, and 80 ohms respectively. The generator serves a 20 kW, 200 V load through a feeder with an equivalent resistance of 0.1 ohm. Solve for the power generated by the armature.

A dc shunt generator has an induced voltage of 220 volts on open circuit. When the machine is on load, the voltage is 200 volts. Find the load current if the field resistance is 100 ohms and armature resistance is 0.2 ohms

A 20 kW, 200 V shunt generator is operated at rated load. If the driving engine is developing 30 hp, determine the iron and friction losses. Armature resistance is 0.05 ohms and shunt field resistance is 50 ohms.

The hysteresis and eddy current losses of a DC machine running at 1000 rpm are 250 watts and 100 watts respectively. If the flux remains constant, at what speed will the total iron loss be halved?

A compound generator is to be operated as a flat-compound long shunt generator. To obtain the same rated voltage at full load and at no load when operated as shunt generator, it is necessary to increase the field current by 0.20 A. The shunt field winding has 1000 turns/pole and the series field winding has 4 turns/pole. If the full load armature current of the compound generator is 95 A and the series field resistance is 0.025 ohm, calculate the diverter resistance required.