DC Motors MCQs

A 4 pole dynamo with wave wound armature has 51 slots containing 20 conductors in each slot. The induced emf is volts and the speed is 8500 rpm. The flux per pole will be

Out of the following factors for a dc machine,(i)Interpole (ii) Armature resistance (iii) Armature Current (iv) Reduction in field current(v) Load current the factors that are responsible for decrease in the terminal voltage of a shunt generator are

The laws of electromagnetic induction (Faraday's and Lenz's law) are summarized in the following equation :di

A 4-pole lap-wound DC generator has a developed power of P watts and voltage of E volts. Two adjacent brushes of the machine are removed as they are worn out. If the machine operates with the remaining brushes, the developed voltage and power that can be obtained from the machine are

A DC shunt motor is running at 1200 rmp, when excited with 220V DC. Neglecting the losses and saturation, the speed of the motor when connected to a 175 V DC supply is

The compensating winding in a dc machine

1n case of an armature controlled separately excited de motor drive with closed-loop speed control, an inner current loop is useful because it

An electric motor with "constant output power" will have a torque-speed characteristic in the form of a

A dc series motor fed from rates supply voltage is overloaded and its magnetic circuit is saturated. The torque-speed characteristic of this motor will be approximately represented by which curve of Fig. 7.2?TorqueFig. 7.2