Electromagnetic Induction Part 2

A conducting circular loop is rotated about its diameter at a constant angular speed of 100rad∕s in a magnetic field of 0.5 T perpendicular to the axis of rotation. When the loop is rotated by 30∘ from the horizontal position, the induced EMF is 15.4 mV . The radius of the loop is ____ mm.
(Take π=‌

22

7

)