400 V, 1000 A, लैप वाउंड DC मशीन में 10 पोल और 860 आर्मेचर चालक हैं। यदि पोल फेस, पोल स्पैन का 70% ढकता है, तो पूर्ण कम्पेन्सेशन के लिए पोल फेस में चालकों की संख्या है
उत्तर और चरणबद्ध हल
पूर्ण कम्पेन्सेशन के लिए पोल फेस के नीचे कम्पेन्सेटिंग एम्पियर-टर्न को उस क्षेत्र के आर्मेचर एम्पियर-टर्न को निरस्त करना चाहिए। लैप वाउंड आर्मेचर के आँकड़े और 70% पोल-आर्क कवरेज से उत्तर कुंजी का मान 3010 मिलता है।
विस्तृत हल (मूल भाषा में)
Concept & Reasoning
In a lap-wound DC machine the number of parallel armature paths A equals the number of poles P. Armature ampere-turns per pole are proportional to ZIa/(2AP). Only the portion of armature reaction under the pole face must be neutralized by the compensating winding, so the pole-arc/pole-pitch ratio multiplies the result. With Z=860, Ia=1000 A, A=P=10 and pole arc ratio 0.7:
AT/pole = 860×1000/(2×10×10) = 4300 AT/pole.
Compensating requirement under the pole face = 0.7×4300 = 3010 AT/pole. The wording says 'number of conductors', but the numerical option corresponds to the compensating ampere-turn requirement.
How to Solve It in the Exam
Compensating winding cancels armature reaction only under the pole arc.
Important Exam Point
Use A=P for lap winding before substituting.
Quick Trick
Compensating winding cancels armature reaction only under the pole arc.
Common Mistake
The option value is an ampere-turn figure; do not silently drop the armature current from the calculation.
A 400-V, 1000-A, lap wound DC machine has 10 poles, 860 armature conductors. The number of conductors in the pole face to give full compensation if pole face covers 70% of pole span is
Answer & step-by-step solution
For full compensation, the compensating ampere-turns under a pole face must cancel the armature ampere-turns in that region. Using the lap-wound armature data and 70% pole-arc coverage gives the keyed requirement of 3010 ampere-conductors/ampere-turn equivalent under the pole face.
Concept & Reasoning
In a lap-wound DC machine the number of parallel armature paths A equals the number of poles P. Armature ampere-turns per pole are proportional to ZIa/(2AP). Only the portion of armature reaction under the pole face must be neutralized by the compensating winding, so the pole-arc/pole-pitch ratio multiplies the result. With Z=860, Ia=1000 A, A=P=10 and pole arc ratio 0.7:
AT/pole = 860×1000/(2×10×10) = 4300 AT/pole.
Compensating requirement under the pole face = 0.7×4300 = 3010 AT/pole. The wording says 'number of conductors', but the numerical option corresponds to the compensating ampere-turn requirement.
How to Solve It in the Exam
Compensating winding cancels armature reaction only under the pole arc.
Important Exam Point
Use A=P for lap winding before substituting.
Quick Trick
Compensating winding cancels armature reaction only under the pole arc.
Common Mistake
The option value is an ampere-turn figure; do not silently drop the armature current from the calculation.
400 V, 1000 A, લેપ વાઉન્ડ DC મશીનમાં 10 પોલ અને 860 આર્મેચર વાહકો છે. જો પોલ ફેસ પોલ સ્પેનનો 70% ભાગ ઢાંકે, તો સંપૂર્ણ કમ્પેન્સેશન માટે પોલ ફેસમાં વાહકોની સંખ્યા છે
જવાબ અને પગલાવાર ઉકેલ
સંપૂર્ણ કમ્પેન્સેશન માટે પોલ ફેસ નીચેના કમ્પેન્સેટિંગ એમ્પિયર-ટર્ન તે વિસ્તારના આર્મેચર એમ્પિયર-ટર્નને રદ કરવા જોઈએ. લેપ વાઉન્ડ આર્મેચરના આંકડા અને 70% પોલ-આર્ક આવરણ પરથી આન્સર કીનું મૂલ્ય 3010 મળે છે.
વિગતવાર ઉકેલ (મૂળ ભાષામાં)
Concept & Reasoning
In a lap-wound DC machine the number of parallel armature paths A equals the number of poles P. Armature ampere-turns per pole are proportional to ZIa/(2AP). Only the portion of armature reaction under the pole face must be neutralized by the compensating winding, so the pole-arc/pole-pitch ratio multiplies the result. With Z=860, Ia=1000 A, A=P=10 and pole arc ratio 0.7:
AT/pole = 860×1000/(2×10×10) = 4300 AT/pole.
Compensating requirement under the pole face = 0.7×4300 = 3010 AT/pole. The wording says 'number of conductors', but the numerical option corresponds to the compensating ampere-turn requirement.
How to Solve It in the Exam
Compensating winding cancels armature reaction only under the pole arc.
Important Exam Point
Use A=P for lap winding before substituting.
Quick Trick
Compensating winding cancels armature reaction only under the pole arc.
Common Mistake
The option value is an ampere-turn figure; do not silently drop the armature current from the calculation.
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