\textbf{70.} A wire in the shape of a circular loop with radius $10\,\text{cm}$ is placed on a horizontal surface. A uniform magnetic field perpendicular to the surface, with a tilt angle of $30°$ from the plane of the loop, decreases from $6000$ gauss to zero in $15.7$ milliseconds. What is the average induced EMF in the loop in volts?
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(1) $0.6\sqrt{3}$ \hspace{2em} (2) $0.6$ \hspace{2em} (3) $1.2\sqrt{3}$ \hspace{2em} (4) $1.2$
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