1.What are the factors that can affect the Factor of safety selection? The factor of safety is used in designing a machine component. Prior to selecting the correct factor of safety certain points must be taken into consideration such as: > The properties of the material used for the machine and the changes in its…
1. Which reactor produces more fissionable material than it consumes ? Ans: Breeder reactor. 2. Which reactor uses natural uranium as fuel ? Ans: Gas cooled reacator. 3. Which reactor uses heavy water as moderator ? Ans: CANDU. 4. Which reactor requires no moderator ? Ans: Breeder reactor. 5. Which reactor uses primary coolant as fluoride salts of lithium, beryllium, thorium and uranium ?…
1. How the analyses and calorific values of fuels can be reported ? Ans: It may be reported as (a) as received or fired (wet) basis (b ) dry or moisture free basis © combustible or ash and moisture free basis 2. What is the difference between nuclear fission and fission chain reaction. Ans: The process of splitting of…
1. Which reactor has no moderator ? Ans: Fast breeder reactor. 2. What are thermal neutrons ? Ans: Thermal neutrons are slow neutrons (having energy below 1 eV) which are in thermal equilibrium with their surroundings. 3. What is big advantage of fast breeder reactor ? Ans: It has rapid self breeding of fissile fuel during the operation of the reactor,…
1. How you can define coal ? Ans: Coal is a naturally occurring hydrocarbon that consists of the fossilised remains of buried plant debris that have undergone progressive physical and chemical alteration, called coalification, in the course of geologic time. 2. Which pollutant is major greenhouse gas and what is its effect ? Ans: CO is major greenhouse gas…
1. Why rockets using liquid hydrogen have higher specific impulse compared to liquid hydrocarbon ? Ans: Liquid hydrogen has higher burning velocity. 2. Why axial flow compressor is preferred for gas turbines for aeroplanes ? Ans: Because it has low frontal area. 3. What is the effect of inter cooling in gas turbines ? Ans: It decreases thermal efficiency but increases…
1. Why pistons are usually dished at top ? Ans: Pistons are usually hollowed at top to (i) provide greater space for combustion, (ii) increase surface for flue gases to act upon, and (iii) better distribution of stresses. 2. What is the function of thermostat in cooling system of an engine ? Ans: Thermostat ensures optimum cooling because excessive…
1. Maximum combustion temperature in gas turbines is of the order of 1100 to 10°C whereas same is around 00°C in I.C. engine ? Why ? Ans: High temperature in I.C. engine can be tolerated because it lasts for a fraction of second but gas turbines have to face it continuously which metals can’t withstand. 2. Why efficiency…
1.Which two elements in feed water can cause corrosion of tubes and plates in boiler? Ans: Acid and oxygen in feed water lead to corrosion. 2. What should be done to prevent a safety valve to stick to its seat ? Ans: Safety valve should be blown off periodically so that no corrosion can take place on valve…
1. When maximum discharge is obtained in nozzle ? Ans: At the critical pressure ratio. 2. Under what condition the work done in reciprocating compressor will be least ? Ans: It is least when compression process approaches isothermal. For this purpose, attempts are made to cool the air during compression. 3. What is the difference between stalling and surging in…