The induced EMF in a loop is given by Faraday's Law of Induction:
\[
\epsilon = - \frac{d\Phi}{dt}
\]
Where \( \Phi \) is the magnetic flux given by:
\[
\Phi = B A \cos \theta
\]
Here:
- \( B = 0.4 \sin(300t) \, T \) (time-dependent magnetic field)
- \( A = (2 \, \text{cm})^2 = (0.02 \, \text{m})^2 = 4 \times 10^{-4} \, \text{m}^2 \) (area of the square loop)
- \( \theta = 60^\circ \) (angle between the magnetic field and the plane of the loop)
Step 1: Calculate the magnetic flux.
\[
\Phi = B A \cos \theta = (0.4 \sin(300t)) \times (4 \times 10^{-4}) \times \cos(60^\circ)
\]
Since \( \cos(60^\circ) = \frac{1}{2} \), we get:
\[
\Phi = 0.4 \times 4 \times 10^{-4} \times \sin(300t) \times \frac{1}{2}
\]
\[
\Phi = 8 \times 10^{-5} \sin(300t) \, \text{Wb}
\]
Step 2: Differentiate the flux to find the induced EMF.
\[
\epsilon = - \frac{d\Phi}{dt}
\]
\[
\epsilon = - \frac{d}{dt} \left( 8 \times 10^{-5} \sin(300t) \right)
\]
\[
\epsilon = - 8 \times 10^{-5} \times 300 \cos(300t)
\]
\[
\epsilon = - 2.4 \times 10^{-2} \cos(300t) \, \text{V}
\]
Step 3: Find the maximum EMF.
The maximum value of \( \cos(300t) \) is 1, so the maximum EMF is:
\[
\epsilon_{\text{max}} = 2.4 \times 10^{-2} \, \text{V} = 24 \, \text{mV}
\]
Thus, the maximum induced EMF is 24 mV.
Final Answer: 24 mV