WBJEE · Physics · Electromagnetic Induction
The magnetic flux linked with a coil satisfies the relation \(\phi=4 t^{2}+6 t+9\) Wb, where \(t\) is the
time in second. The emf induced in the coil at \(t=2 \mathrm{s}\) is
- A \(22 \mathrm{V}\)
- B \(18 \mathrm{V}\)
- C \(16 \mathrm{V}\)
- D \(40 \mathrm{V}\)
Answer & Solution
Correct Answer
(A) \(22 \mathrm{V}\)
Step-by-step Solution
Detailed explanation
Given \(\phi=4 t^{2}+6 x+9\) and \(t=2 \mathrm{s}\) We know that \(\varepsilon=\frac{d \phi}{d t}\) Here, \(\frac{d \phi}{d t}=8 t+6\) \[ \begin{aligned} \left(\frac{d \phi}{d t}\right)_{t=2} &=8 \times 2+6 \\ \varepsilon &=22 \mathrm{V} \end{aligned} \]
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