List of top Mechanical Engineering Questions

Which one of the following is a solid state joining process?
In which of the following process, the state of stress of the material undergoing deformation is only shear?
Straight polarity in arc welding is obtained with
The shear strength of a sheet metal is 300 MPa. The blanking force required to produce a blank of 100 mm diameter from a 2 mm thick sheet is close to
A stock of thickness 30 mm is to be rolled to 10 mm in a single stage. What is the minimum diameter of the rolls, if the maximum angle of bite is 60°?
In cold working of metals, the working temperature is
Name the four processes A, B, C, and D, shown in Figure, in the same sequence.
For a ductile material, toughness is a measure of
A spherical drop of molten metal of radius 5 mm was found to solidify in 12 s. In how much time will a similar drop of radius 10 mm solidify?
In a gating system, the ratio of 1:2:4 represents:
Select the correct statement for the riser design
The coordination number for a Body-Centred Cubic (BCC) structure is
Primary object of full annealing is to
If H is the available head for a hydraulic turbine, the speed (N), the discharge (Q), and the power (P), respectively are proportional to
According to the direction of flow through the runner, Kaplan turbine is a:
A Pitot-tube is used for measuring
According to the Darcy--Weisbach equation, the loss of head for flow through a circular pipe is (\( L \)-length of the pipe, \( D \)-diameter of the pipe, \( V \)-velocity of flow, \( f \)-friction factor)
Which of the following represents the equation of continuity for a steady compressible fluid? \( \vec{V} \) represents the velocity vector; \( \rho \) represents density
For stable equilibrium of floating bodies, the centre of gravity has to:

Identify the correct combination of turbines classification based on the head of the water.

A fluid, with viscosity 1.5 Pa.s and density 1260 kg/m³, flows at a velocity of 5 m/s in a 150 mm diameter pipe. The Reynolds number is:
The effectiveness of a heat exchanger is defined as the ratio of the actual heat transfer rate to
In a heat exchanger, the hot gases enter with a temperature of 150 °C and leave at 75 °C. The cold fluid enters at 25 °C and leaves at 125 °C. The capacity ratio of the exchanger is:

What is the relation for the pressure difference \( P_1 - P_2 \) for the flow device shown in Figure? (\( \rho \) is density of the fluid; \( a, h \) are column heights)

What is the pressure within a 1 mm diameter spherical droplet of water relative to the atmospheric pressure outside? The surface tension of water is 0.07 N/m.