A. Filmwise condensation gives a lower heat transfer rate than the dropwise condensation
B. Suitable coating or vapour additive is used to promote film wise condensation
C. If a condensing liquid does not wet the surface dropwise, even then condensation will take
place on it
D. Reynolds number of condensing liquid is based on its mass flow rate
Related Mcqs:
- Pick out the correct statement?
A. Hot worked materials are subjected to annealing to remove internal stresses
B. Annealing of steel hardens it slightly
C. Normalising of a material induces stresses
D. Tempering of a material improves ductility & toughness but reduces hardness & brittleness - Pick out the correct statement ?
A. Jet engine can work, where there is no atmosphere
B. Rocket engines cannot work, where there is no atmosphere
C. Rocket engines carry oxygen required for the combustion in the form of oxidiser
D. Jet engines also carry oxidiser - Moist air is cooled along the line of constant ________________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs ?
A. Enthalpy
B. Relative humidity
C. Wet bulb temperature
D. Dew point temperature - Pick out the correct combination about the role of various additives used in polymers ?
A. Plasticiser: increases the polymer strength
B. Heat stabiliser: increases the maximum service temperature
C. Fillers: Does not affect the property of polymer but increases its weight
D. Lubricants: increases the flexibility of polymers - Pick out the wrong statement about the machinability of metals. Machinability of a metal ?
A. Decreases with increase in strain hardening tendencies
B. Decreases with increase in hardness, in general
C. Depend on the composition, microstructure and physical & mechanical properties
D. Decreases with increases in tensile strength & decrease in grain size - Pick out the wrong statement?
A. Processing of thermosetting plastics is ideally done by injection moulding
B. Processing of thermoplastics is ideally done by compression moulding
C. Mass production of seamless pipes are done by electrical resistance welding (ERW)
D. Stretch forming is a process of cold drawing - Pick out the wrong statement ?
A. Seam welding, projection welding & spot welding are the classification of electrical resistance
welding
B. Electrode tip in spot welding is of copper and the tip diameter should be equal to t (where, t =
plate thickness to be welded)
C. In spot welding, two pieces to be joined are overlapped and placed between two electrodes
D. Mild steel sheet cannot be spot welded - Pick out the wrong statement ?
A. The X-rays cannot be deflected by electric field unlike cathode rays
B. The intensity of X-rays can be measured by ionisation current produced due to the ionisation
of gas by X-rays
C. The quality of X-rays can be controlled by varying the anode-cathode voltage
D. Crystal structure of a material can be studied by an electron microscope - Pick out the wrong statement?
A. Ductile fracture of a stressed material, which exhibits a large plastic deformation is commonly
caused by the formation and coalescence of voids in the necked region
B. Brittle fracture is caused by the propagation of pre-existing cracks in the material and involves minimum plastic deformation
C. Fatigue fracture of a material is always brittle in nature and takes place due to the existence of
line imperfections
D. Brittle materials are generally tested in tension - Pick out the wrong statement ?
A. The equivalent stiffness of two springs (of equal stiffness ‘S’) in series is S/2 while in parallel
is 2S
B. For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire
diameter)
C. Crushing load or columns is less than the buckling load
D. Modulus of resilience is proportional to (stress at elastic limit)2
