Engineering Mechanics Gate Previous Year Questions

Which of the following is responsible for eddy viscosity (or turbulent viscosity) in a turbulent boundary layer on a flat plate?

a) Nikuradse stresses
b) Reynolds stresses
c) Boussinesq stresses
d) Prandtl stresses

Which of the following conditions is used lo determine the stable equilibrium of all partially submerged floating bodies?

a) Centre of buoyancy must be below the centre of gravity
b) Metacentre must be at a higher level than the centre of gravity
c) Centre of buoyancy must be above the centre of gravity
d) Metacentre must be at a lower level than the centre of gravity

In the space above the mercury column in a barometer tube, the gauge pressure of the vapour is

a) zero
b) negative
c) positive, but less than one atmosphere
d) positive, but more than one atmosphere

A spur gear with 20° full depth teeth is transmitting 20 kW at 200 rad/s. The pitch circle diameter of the gear is 100 mm. The magnitude of the force applied on the gear in the radial direction is

a) 0.36 kN
b) 0.73 kN
c) 1.39 kN
d) 2.78 kN

Pre-tensioning of a bolted joint is used to

a) strain harden the bolt head
b) decrease stiffness of the bolted joint
c) increase stiffness of the bolted joint
d) prevent yielding of the thread root