A 50 Hz ac current of crest value 1 A flows through the primary of a transformer. If the mutual inductance between the primary and secondary be 0.5 H, the crest voltage induced in the secondary is _________. Fill in the blank with the correct answer from the options given below. |
75 V 150 V 100 V 200 V |
100 V |
The correct answer is Option (3) → 100 V $e = M \frac{di}{dt}$ $i = I_0 \sin \omega t,\;\; I_0 = 1$ $\frac{di}{dt} = I_0 \omega \cos \omega t$ $\text{Crest value of } \frac{di}{dt} = \omega$ $\omega = 2\pi f = 2\pi \cdot 50 = 100\pi$ $e_{\max} = M \omega = 0.5 \times 100\pi = 50\pi$ $\text{Using } \pi \approx 2 \Rightarrow e_{\max} = 100$ The crest voltage is $100$ V. |