Questions and answers for exam Preparation

MCQs

Total Questions : 5013 | Page 494 of 502 pages

Question 4931. Increase in temperature, in general results in the____________________?

Decrease in the viscosities of both liquids & gases
Increase in the viscosities of both liquids & gases
Increase in the viscosity of liquids and decrease in that of gases
Decrease in the viscosity of liquids and increase in that of gases

Discuss Question

Answer: Option D. -> Decrease in the viscosity of liquids and increase in that of gases
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4932. In case of a, centrifugal pump, the ratio h1/h2 is termed as the _____________ efficiency (where, h1 = actual measured head & h2 = head imparted to the fluid by impeller)?

Mechanical
Overall
Volumetric
Impeller

Discuss Question

Answer: Option A. -> Mechanical
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4933. A semi-conductor is damaged & behaves like a conductor, on passing a strong electric current through it, because it heats up the crystals & breaks the covalent bonds resulting in _______________ electrons ?

Lack of free
Excess of
Decrease in
None of these

Discuss Question

Answer: Option B. -> Excess of
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4934. Nusselt number/Biot number varies___________________?

Inversely with thermal conductivity
Directly with heat transfer co-efficient
Directly with thermal conductivity
Inversely with the dimension of the solid

Discuss Question

Answer: Option A. -> Inversely with thermal conductivity
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4935. In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be__________________?

Conduction
Radiation
Natural convection
Forced convection

Discuss Question

Answer: Option B. -> Radiation
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4936. Pick out the wrong statement about coating/electroplating of metals ?

Phosphate coating is used as an excellent base for paints & enamels
Phosphate coating is less corrosion resistant than chromate coating
The base metal to be electroplated is normally made the cathode of the electrolytic cell and coating metal is made the anode
Calorising is the process of coating steel with chromium

Discuss Question

Answer: Option D. -> Calorising is the process of coating steel with chromium
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 4937. Cupola produces _________________ iron?