Q. A standard vapor compression refrigeration cycle operating with a condensing temperature of 35oC and an evaporating temperature of -10 oC develops 15 kW of cooling. The p–h diagram shows the enthalpies at various states. If the isentropic efficiency of the compressor is 0.75, the magnitude of compressor power (in kW) is ________(correct to two decimal […]
Q. Air is held inside a non-insulated cylinder using a piston (mass M=25 kg and area A=100 cm2) and stoppers (of negligible area), as shown in the figure. The initial pressure Pi and temperature Ti of air inside the cylinder are 200 kPa and 400°C, respectively. The ambient pressure P¥ and temperature T¥ are 100 kPa and
Q. A 0.2 m thick infinite black plate having a thermal conductivity of 3.96 W/m-K is exposed to two infinite black surfaces at 300 K and 400 K as shown in the figure. At steady state, the surface temperature of the plate facing the cold side is 350 K. The value of Stefan- Boltzmann constant,
Q. A frictionless circular piston of area 10-2 m2 and mass 100 kg sinks into a cylindrical container of the same area filled with water of density 1000 kg/m3 as shown in the figure. The container has a hole of area 10-3 m2 at the bottom that is open to the atmosphere. Assuming there is
Q. A force of 100 N is applied to the centre of a circular disc, of mass 10 kg and radius 1 m, resting on a floor as shown in the figure. If the disc rolls without slipping on the floor, the linear acceleration (in m/s2) of the centre of the disc is _________(correct to two
Q. A bar is subjected to a combination of a steady load of 60 kN and a load fluctuating between -10 kN and 90 kN. The corrected endurance limit of the bar is 150 MPa, the yield strength of the material is 480 MPa and the ultimate strength of the material is 600 MPa. The
Q. A thin-walled cylindrical can with rigid end caps has a mean radius R = 100 mm and a wall thickness of t = 5 mm. The can is pressurized and an additional tensile stress of 50 MPa is imposed along the axial direction as shown in the figure. Assume that the state of stress in
Q. Air flows at the rate of 1.5 m3/s through a horizontal pipe with a gradually reducing cross- section as shown in the figure. The two cross-sections of the pipe have diameters of 400 mm and 200 mm. Take the air density as 1.2 kg/m3 and assume inviscid incompressible flow. The change in pressure (
Q. A bimetallic cylindrical bar of cross sectional area 1 m2 is made by bonding Steel (Young’s modulus = 210 GPa) and Aluminium (Young’s modulus = 70 GPa) as shown in the figure. To maintain tensile axial strain of magnitude 10-6 in Steel bar and compressive axial strain of magnitude 10-6 in Aluminum bar, the
A bimetallic cylindrical bar of cross sectional area 1 m2 is made by bonding Steel Read More »
Q. In a cam-follower, the follower rises by h as the cam rotates by δ (radians) at constant angular velocity ω (radians/s). The follower is uniformly accelerating during the first half of the rise period and it is uniformly decelerating in the latter half of the rise period. Assuming that the magnitudes of the acceleration
