Identify Faraday's Law

According to Faraday's Law of electromagnetic induction, the induced electromotive force ($V_{emf}$) is defined as the negative rate of change of magnetic flux linkage.

$V_{emf} = -\frac{d\lambda}{dt}$

Differentiate Flux Linkage

Given flux linkage $\lambda = 2t^2$. Differentiating this with respect to time $t$ gives:

$\frac{d\lambda}{dt} = \frac{d}{dt}(2t^2) = 4t$

Calculate Magnitude at t = 1

Substitute $t = 1$ second into the derivative expression to find the magnitude of the EMF.

$|V_{emf}| = |4(1)| = 4 \text{ Volts}$