Question
Give expression for induced emf in AC generator. Discuss, with fogure, how this emf changes with time during one rotation of coil.
✓
Answer
→Expression for induced emf in AC generator is
$\varepsilon=\varepsilon_0 \sin \omega t$
where $\varepsilon_0= NBA \omega$
→Induced emf changes periodically with time during one complete rotation. This is shown step-wise in following figure of graph of emf $\varepsilon \rightarrow$ time $t$. Time $t$ is in the form of periodic time T.
→It is clear that when $\theta=\frac{\pi}{2}$ or $\frac{3 \pi}{2}$, induced emf is maximum.
→When $\theta=0$ or $\pi, 2 \pi$ induced emf is zero.
→This situation is repeated till rotation of coil continues and induced emf $\varepsilon$ is produced between $+\varepsilon_0$ and $-\varepsilon_0$.
$\varepsilon=\varepsilon_0 \sin \omega t$
where $\varepsilon_0= NBA \omega$
→Induced emf changes periodically with time during one complete rotation. This is shown step-wise in following figure of graph of emf $\varepsilon \rightarrow$ time $t$. Time $t$ is in the form of periodic time T.
→It is clear that when $\theta=\frac{\pi}{2}$ or $\frac{3 \pi}{2}$, induced emf is maximum.
→When $\theta=0$ or $\pi, 2 \pi$ induced emf is zero.
→This situation is repeated till rotation of coil continues and induced emf $\varepsilon$ is produced between $+\varepsilon_0$ and $-\varepsilon_0$.
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