The torque required to overcome viscous resistance of a collar bearing is (where R1 and R2 = External and internal radius of collar)

• A. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/179-350-1.png">
• B. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/179-350-2.png">
• C. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/179-350-3.png">
• D. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/179-350-4.png">