Question

An induced current of 2 A flows through a coil. The resistance of the coil is 100 \( \Omega \). What is the change in magnetic flux associated with the coil in 1 ms?

• A. \( 2 \times 10^{-2} \, \text{Wb} \)
• B. \( 2 \times 10^{-3} \, \text{Wb} \)
• C. \( 22 \times 10^{-2} \, \text{Wb} \)
• D. \( 2 \times 10^{-4} \, \text{Wb} \)

Answer 1

The Correct Option is B

The change in magnetic flux is related to the induced current by Faraday's Law of Induction:\( \mathcal{E} = - \frac{d\phi}{dt} \)
where \( \mathcal{E} \) is the induced emf, and 
\( d\phi \) is the change in magnetic flux. 

The induced emf is also related to the current and the resistance of the coil by Ohm's Law:
\( \mathcal{E} = I \cdot R \) 

Substituting the given values:\( \mathcal{E} = 2 \times 100 = 200 \, \text{V} \) 
Now, using Faraday's Law to find the change in flux: \( d\phi = \mathcal{E} \cdot dt = 200 \times 10^{-3} = 2 \times 10^{-3} \, \text{Wb} \)