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Q106EasyDC Machines

DC मोटर में प्रेरित emf सप्लाई वोल्टेज के प्रति कैसी प्रतिक्रिया करता है?

उत्तर और चरणबद्ध हल
सही उत्तर: C. यह सप्लाई वोल्टेज का विरोध करेगा
संक्षिप्त व्याख्या

चलती DC मोटर में प्रेरित आर्मेचर emf बैक emf है। लेन्ज़ के नियम से यह लागू सप्लाई वोल्टेज का विरोध करता है और गति बढ़ने पर आर्मेचर करंट सीमित करता है।

विस्तृत हल (मूल भाषा में)

Concept & Reasoning

When the armature of a DC motor rotates in the magnetic field, an emf is induced in its conductors. The direction of that induced emf is governed by Lenz's law: it opposes the cause producing it. Since the supply causes the armature to rotate, the induced emf acts opposite to the supply and is therefore called back emf. The armature circuit is commonly written V = Eb + IaRa (neglecting brush drop). At starting Eb = 0, which explains the high starting current; as speed rises, Eb rises and current falls.

How to Solve It in the Exam

Motor induced emf = back emf = opposes supply.

Important Exam Point

Use the armature-voltage equation to connect back emf with starting-current behavior.

Quick Trick

Motor induced emf = back emf = opposes supply.

Common Mistake

Do not confuse motor back emf with generator emf polarity; both follow electromagnetic induction but circuit roles differ.

Solution diagram – DC मोटर में प्रेरित emf सप्लाई वोल्टेज के प्रति कैसी प्रतिक्रिया करता है?
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