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Answer the third and fourth part of question no.28

Q.28. (iii) Derive the expression for maximum value of the induced emf and state the induced emf and state the rule that gives the direction of the induced emf.

(iv) Show the variation of the emf generated versus time as the armature is rotated with respect to the direction of the magnetic fields.

$fluxvariesaccordingtoeqn\phantom{\rule{0ex}{0ex}}\varphi =NBA\mathrm{cos}\omega t\phantom{\rule{0ex}{0ex}}e=\frac{-d\varphi}{dt}=NBA\omega \mathrm{sin}\omega t\phantom{\rule{0ex}{0ex}}maximumvalueofinducedEMF{E}_{max}=NBA\omega \phantom{\rule{0ex}{0ex}}byflemingrighthandrulewegetthedirectionofinducedcurrent.\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}$

Regards

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