The required rated voltage applied to a six leads out motor are a. 760-volts and 440-volts c. 440-volts and 254-volts b. 220-volts and 127-volts d. All of the above The rotating parts of an AC machines is a. Field winding and the core c. Wound Rotor winding b. Armature winding and the core d. All of these

The required rated voltage applied to a six leads out motor are a. 760-volts and 440-volts c. 440-volts and 254-volts b. 220-volts and 127-volts d. All of the above The rotating parts of an AC machines is a. Field winding and the core c. Wound Rotor winding b. Armature winding and the core d. All of these

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter33: Single-phase Motors

Section: Chapter Questions

Problem 32RQ

See similar textbooks

Similar questions

The resistance of the shunt winding of a d.c machine is measured before and after a run of several hours. The average values are 55 ohms and 63 ohms. Calculate the rise in temperature of the winding (Temperature coefficient of resistance of copper is 0.00428 ohm per ohm per °C). [36°C]
Q choose the correct answer: 1-Brushless excitation system consisting of.... a- Stator field winding and power diodes b-stator and rotor field winding and capacitor c- stator and rotor field winding and capacitor d- Everything mentioned in the options 2- Voltage generated per phase in an alternator is proportional to a- Flux per pole b- Number of turns in armature c-Winding factors d- Everything mentioned in the options e- Frequency of waveform 3- If input mech. Power of SG constant, the functionality of AVR is a- Control flux of rotor b-Control terminal voltage c- Control flux and terminal voltage d-Control Load angle
DEGREE: ELECTRICAL ENGINEERING SUBJECT/COURSE: AC MACHINES Answer the following questions (A, B and C) depending on the topic. 1. ALTERNATORS A. Why is it necessary to maintain the speed of an alternator at all times and how do they control the speed of an alternator when in operation? B. Distinguish between half-coiled and full-coiled armature windings in alternators. C. Why are fractional pitch windings generally used in alternators?
a)Please explain the connection methods of Current and Voltage Transformers? b) Control the DC motor speed and direction. Draw the circuit.
4. e principle of operation of a 3-phase. Induction motor is most similar to that of a (a) synchronous motor (b) DC motor (c) transformer with a shorted secondary (d) SPIM 5. 500 kW, 3-phase, 440 volts, 50 Hz, A.C. induction motor has a speed of 960 r.p.m. on full load. The machine has 6 poles. The slip of the machine will be (a) 0.01 (b) 0.02 (c) 0.03 (d)0.04 6. A centrifugal switch is used to disconnect 'starting winding when motor has (a) picked up about 50 to 75 per cent of rated speed (b) picked up about 10 to 15 per cent of rated speed (c) run for about 1 minute (d) run for about 5 minutes 7- A 6-pole, 50-Hz, 3-0 induction motor is running at 950 rpm and has rotor Cu loss of 6 kW. Its rotor input is......kW (a) 120 (b) 60 (c) 6.3 (d) 66 8- The number of slip rings on a squirrel cage induction motor is usually (a)Two (b) Three (c) Four (d) None
Fill in the following blanks:1. Lap winding is suitable for ……. Voltage, …… current d.c. generators.2. The critical resistance of the d.c. generator is the resistance of ……. .
vii. Why Induction motor is called rotating transformer?
A 2-pole d.c. shunt generator has a useful flux per pole of 0.03 Wb. The armature winding consist of 200 turns, each of 0.005 Q resistance. Calculate the terminal voltage when running at 1200 r.p.m. if the * .armature current is 40A
9- If the field current circuit of DC shunt generator is opened, there will no induced voltage in armature winding. 10-If the transformation ratio greater than 1, the transformer called step-up transformer.
14/. The purpose of brushes in a dc machine is__________. to change ac to dc signal to remove the losses in machine to collect voltage from windings avoid spark for current
A 4 pole , lap wound , d c shunt generator has a useful flux per pole of 0.07 wb. the armature winding consist of 220 turns each of 0.004 ohm resistance . calculate the terminals voltage when running at 900 r.p.m if the armature current is 50 A.
er C ai Exa (B)- Select the correct answer for the alternatives given. 1- A d.c. shunt motor is running with certain load. The effect of adding an external resistance field circuit is to a)-reduce the motor speed, b)-increase the motor speed, c)- stop the motor d)- reduce the armature current of the motor 2- The copper loss and iron loss of transformer at half load are 1600 w and 5000w respectively. The copper loss and iron loss at full load will be respectively. a)-(3200 w and 10000w), b)- (6400 w and 5000 w), c)-(6400 w and 10000w), d)- (3200 w and 1250w) Way t 3- The secondary winding of which of the following transformer is always kept close b)- auto-transformer, c)- current transformer, a)-power transformer d)-distribution transformer 4- A 6-pole lap wound de shunt generator is supplying 295 A to load. The field current of generator is 5A. The current parallel path is a)-300A 245)-145A b)- 150A, c)- 50A باب الثاني