why field resistance is higher than armature resistance in
dc machines? and why filed resistance is kept at min value
at starting in same time of armature resistance at max value?
Answers were Sorted based on User's Feedback
Answer / sai
To allow the maximum current through the armature, resistance is kept to very low value. According to ohm's law, V=IR.
As R is very low then current becomes maximum.
| Is This Answer Correct ? | 21 Yes | 10 No |
Answer / lokesh luckky
It has two reasons
1) in DC generator to allow large generated currents to output.
2)in motor (torque is proportional to current) so to produce high torque we must allow high currents through winding.
| Is This Answer Correct ? | 7 Yes | 0 No |
Answer / abdelbaset
because the consumable power in the field circuit assuming
the same voltage of the main circuit is lower than the
armature circuit. so the excitation current is lower than
armature current so field resistance is greater than
armature resistance
| Is This Answer Correct ? | 11 Yes | 16 No |
Answer / binod
field resistance always more than the armature resistance
of a d.c machine(shunt or series or compound).magnetic flux
created by field.to vary generate e.m.f the field
resistance vary from min to max with increase/decrease of
speed.in motor case the speed can be vary by varrying the
field resistance(addition or substraction) with the
required torque.
| Is This Answer Correct ? | 6 Yes | 19 No |
In single phase capacitor motor, if the motor rotate reverse direction then how much power will be consumed by the motor and why?
is there any role of power factor with frequency variation? and how we can manage the frequency variation?
PLEASE TELL ME ABOUT QUESTION PAPER OF UPCL ENTERENCE EXAM.
please tell me the all the spcications of the 100MW 11KV HYDEL POWER PLANT SPECICATIONS
Don't you have similar question banks related to Oral Certification Examination conducted by Mercantile Marine Departments / Directorate of Shipping, Ministry of Shipping for Electro Technical Officer?
0 Answers Bernhard Schulte Shipmanagement,
Is it posssible to obtain the higher speed(3000rpm) for adiferentiallly cascaded induction motors(with 8 and 6 poles)
A thermistor is a type of
hello everybody...i m an Elelctrical Engineering student.. i m in final year.. i m attending IOCL interview on 2nd aug. kindly let me know on wat subjects to concentrate more...any body who has attended the interview can help... others can also post their views... thankyou.
what type of transformer used in soft ware parks its distribution or power transformer. like 1800 kva
Can any one explain me about 2 phase motors ?
Explain UPS
Can step down transformer works as step up one???
Civil Engineering (5086)
Mechanical Engineering (4456)
Electrical Engineering (16639)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)