5. A 220-volt shunt motor draws 64-Amp and runs at 500 rpm. Armature resistance, 0.25- ohm, field resistance 55-ohm. Find the speed when a resistor of 20-ohm is included in the shunt field circuit, the load torque remaining the same. Assume the flux to be proportiona to the field current.

On full load a 500 V series motor takes 100 A and runs at 820 rpm. The armature and series field resistances are 0.1 and 0.04 ohm respectively. What will be its speed when developing half-full load torque and with a 0.08 ohm diverter connected across the series field winding. Assume flux is proportional to the field current.

A 900 rpm, 4 pole lap wound shunt motor takes 300 A. The flux per pole is 0.02 Wb and the armature has 1500 conductors. The shunt field takes 4 A of current. Solve for back emf (V).

A 230 V dc series motor has an armature resistance of 0.2 ohm and field resistance of 0.1 ohm at rated voltage. The motor draws a line current of 40 amperes and runs at a speed of 1000 rpm. Find speed of the motor for line current of 20 A at 230 V. Assume that flux at 20 A line current is 60% of flux at 40 A line current.

A 10 kW, 250 V Shunt motor has an armature resistance of 0.5 ohm and a field resistance of 200 ohm. At no load and rated voltage, the speed is 1200 rpm and the armature current is 3 A. At full load and rated voltage, the line current is 47 A and because of armature reaction, the flux is 4 % less than it no load value. a.) What is the full load speed? b.) What is the developed torque at full load?

A 240 V shunt motor has an armature current of 15 A when running at 800 rpm against full-load torque. The armature resistance is 0.6 ohm. What resistance must be inserted in series with the armature to reduce the speed to 400 rpm at the same torque? What will be the speed if the load torque is halved with this resistance in the circuit? Assume the flux to remain constant throughout.

1. The operation of Commutator in DC Motor is * O a) to convert dc to ac O b) to convert ac to dc O c) to convert fixed dc to variable dc O reverse the current direction in the rotating windings each half turn

Q4/B/ What are the principal characteristics of a series DC motor? What are its uses? Core Mc

Examine the saddle torque of induction motors and the effect of different groove structures on the saddle torque.

True or fulse