The loss of torque due to the viscosity of the lubricant is

Question

A journal bearing has a shaft diameter of 40 mm and a length of 40mm. the shaft is rotating at 20 rad/s and the viscosity of the lubricant is 20 mPa-s. The clearance is 0.020mm. The loss of torque due to the viscosity of the lubricant is approximately:                                                                                                                        

      (a) 0.040 Nm                                                      (b) 0.252 Nm

      (c) 0.400 Nm                                                      (d) 0.625 Nm