A uniform magnetic flux density of `0.1 Wbm^(-2)` extends over a plane circuit of area `1m^(2)` and is normal to it. How quickly must the field be reduced to zero if an emf of 100 volt is to be induced in the circuit?

Explanation

To solve the problem, we will use Faraday's law of electromagnetic induction, which states that the induced electromotive force (emf) in a circuit is equal to the negative rate of change of magnetic flux through the circuit.

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Magnetic flux density, \( B = 0.1 \, \text{Wb/m}^2 \)
- Area of the circuit, \( A = 1 \, \text{m}^2 \)
- Induced emf, \( \mathcal{E} = 100 \, \text{V} \)
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