In block brake, the normal reaction and frictional force act at the mid-point of the block. This is true only if the angle of contact is ____

Related MCQs

• A single block brake as shown in Fig.6 has a brake drum diameter of 1m and the angle of contact is 300. It takes 280 Nm torque at 300rpm. The coefficient of friction is 0.35. Determine the required force 'P' to be applied when the rotation of drum is clockwise.
• In a simple band brake applied to a shaft carrying a flywheel of mass 250kg and radius of gyration 350mm , one end of the band is attached to the fulcrum and the other at a distance 300 mm from the fulcrum. The angle embraced by the band is 2250 and the brake drum diameter is 220 mm coefficient of friction 0.25 and the shaft speed is 300 rpm clockwise. Determine the brake torque when a force of 150 N is applied
• When the frictional force helps the applied force in applying the brake, the brake is____.
• For uniform pressure the ratio of frictional torque for a flat collar bearing to the frictional torque for conical collar bearing is equal to____. Where ϴ=semi-angle of the cone
• For uniform wear, the ratio of frictional torque for a flat collar bearing to the frictional torque for conical collar bearing is equal to____. Where ϴ=semi-angle of the cone
• Refer fig.4. It shows a band brake arrangements. The brake to work with force at A upwards and direction of drum clockwise____.
• In a differential band brake, as shown in fig.1the length OA is greater than OB. In order to apply the brake, the force at C should____.
• In a self locking brake, the force required to apply the brake is_____.
• A short shoe brake has angle of contact less than____degree.
• Following are the details pertaining to thrust bearing 1) External and internal dia of contacting surfaces-320 mm and 200 mm resp. 2) Axial load-80 kN 3)Pr. Intensity-350 kN/m2 4) shaft speed-400 rpm 5)coefficient of friction-0.06 Calculate power lost in overcoming friction. the frictional torque and power lost in frictional