GATE 2018 ME (ME1) – Question 63
The clockwise external drum shown engages a short shoe at Y on rigid lever XYZ, hinged at X. A 100 N force acts at Z as shown. With friction coefficient 0.3, braking torque, to two decimals, is ______ N m. All diagram dimensions are in mm.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 8.00 to 9.00
Explanation
Clockwise drum motion pulls the upper shoe rightwards. Moment equilibrium about X gives $100(300)+0.3N(300)-N(200)=0$, hence N = 272.727 N. Braking torque is $\mu NR=0.3(272.727)(0.1)=8.18$ N m. Friction assists the applied lever force.