A cylinder of iron of volume 8 x 10-3 m3 revolves for 20

Question

A cylinder of iron of volume 8 x 10^-3 m³ revolves for 20 minutes at a speed of 3,000 r.p.m. in a two pole field of flux density 0.8 Wb.m².

If the hysteresis coefficient of iron is 753.6 joule/m³ , specific heat of iron is 0.11, the loss due to eddy current is equal to that due to hysteresis and 25% of the heat produced is lost by radiation, find the temperature rise of iron.

Take density of iron as 7.8 x 10³ kg/m³.