121⟩ What are the advantages of diesel engines?
The advantages of diesel engines are:
* a) Fuel economy
* b) Less maintenance
* c) Run cooler
* d) More power @ lower RPM's
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164 Mechanical Engineering Questions And Answers
122⟩ What is the difference between hydraulic oil and engine oil?
Both the hydraulic and engine oils are made from base oils with additives mixed in. The additives used change the characteristics of the oils so that they function differently.
Generally, hydraulic oils (final product including additives) are expected to have very low compressibility and very predictable friction and viscosity stability under pressure.
Generally engine oils (Engine Lubrication Oils anyway) are intended to have high resistance to heat (degradation including chemical and viscosity due to heat) resistance to burning and resistance to absorption of fuels and chemical compounds produced during combustion.
Both classes of oils are likely to have additives intended to provide detergency and to reduce foaming.
Base oils are most commonly petroleum oil bases due to cost, but other bases oil can be used including mineral oils (especially for hydraulic oils) and plant oils (especially for engine oils) and oils from animal sources.
123⟩ Which country has the worlds most powerful tank?
Germany, USA, Russia, and France have the most powerful tanks. Germany's is probably the best after all the USA's man tank the Abrams Uses the German Gun.
124⟩ What does angular momentum mean?
Angular momentum is an expression of an objects mass and rotational speed.
Momentum is the velocity of an object times it is mass, or how fast something is moving how much it weigh. Therefore, angular momentum is the objects mass times the angular velocity where angular velocity is how fast something is rotating expressed in terms like revolutions per minute or radians per second or degrees per second.
125⟩ What is the role of nitrogen in welding?
Nitrogen is used to prevent porosity in the welding member by preventing oxygen and air from entering the molten metal during the welding process. Other gases are also used for this purpose such as Argon, Helium, Carbon Dioxide, and the gases given off when the flux burns away during SMAW (stick) welding.
126⟩ Can you use motor oil in a hydraulic system?
Hydraulic fluid has to pass a different set of standards than motor oil. Motor oil has tackifiers, lower sulfur content, and other ingredients that could prove harmful to the seals and other components in a hydraulic system. If it is an emergency only should you do it.
127⟩ Is Knowledge of properties of engineering materials is significant in pattern making why?
Yes very important, wheels on car are spun on very hard steel die's not aluminum, the properties of the two metals are very different, one is soft, and the other is hard, (the wearing-out of the metals with extended use). In addition, how materials interact with each other as in coexistence and enhancement. Many things swell and shrink with heat and cold, linen is easier to sew then fleese, patternmakers must take in all factors concerning the product they are working with.
128⟩ What kind of paper airplane flies the farthest?
Thickest paper has the greatest mass and therefore potential energy. Potential energy equals kinetic energy (speed). Speed equals lift. Lift equals a greater flight distance. Thicker planes fly farther.
129⟩ What is the difference between upstream and downstream in a refinery?
The total process of a the refining business starts at the oil field or gas field and runs all the way to the sending of processed hydrocarbon to a final user.
Upstream applies to the operation of exploration, drilling, hydrocarbon production, and transmission via truck, rail or ship or pipeline to the refinery intake valve.
Downstream includes all work done at the refinery, distillation, cracking, reforming, blending storage, mixing and shipping.
The case of heavy oil processing (oil sands etc.) and gas plant operation tend to cross the boundaries somewhat. Most are regarded as upstream operations even though downstream type operations are part of the processes. The production of chemical side products at gas plants (e.g. sulfur) is not generally segregated as a "Chemical Plant" operation.
Additional hydrocarbon production operations such as saddle plants, which remove a component from pipeline gas, are generally lumped with upstream.
130⟩ How much water pressure will come from gravity feed tank, which is 10 metres high?
956 pounds per square inch (psi)
131⟩ What causes white smoke in two stroke locomotive engines?
That is the engine running too lean (lack of fuel). This condition will lead to overheating and failure of the engine.
132⟩ How does hydraulics work?
A positive displacement pump (gear, vane, or piston pump) is driven by a prime mover (Electrical Motor or Engine) it sucks fluid from reservoir and delivers oil to system. During loading, a resistance to flow creates the pressure, which is utilized to do the work through cylinder for linear motion, or through hydraulic motor for rotary motion, Direction of flow is changed with help of direction control valve & system pressure is regulated by pressure control valve & flow is regulated by flow control valve.
133⟩ What color are thermal oil piping lines?
Brownish and sort of grey
134⟩ What are examples of mechanisms?
Examples of mechanisms are the workings of a clock, a light switch, and a nail clipper.
135⟩ What is the strongest pistol in the world?
Single shot pistol that shot a .50 BMG round is strong and could have been the strongest in the world.
136⟩ How many BTU per Hour equals 1 Ton of Air Conditioning?
Air conditioners are rated in three ways, by B.T.U.'s, Tons of Refrigeration, or by Horsepower. One Ton of Refrigeration removes the amount of heat needed to melt one ton of ice in 24 hours. One Ton of Refrigeration can remove 12,000 B.T.U.'s of heat in one hour. The B.T.U. is the amount of heat needed to raise 1 lb. of pure water 1 deg F.
137⟩ How is a submarine able to submerge and surface?
Submarines have ballast tanks. The tanks can hold air, or they can be "vented" and water can flow into them and fill them completely. When the tanks are full of air, the submarine is buoyant and floats. When the main vents are opened, the tanks are flooded and the submarine submerges. When the submarine is submerged, wants to surface, air can be injected at high pressure into the ballast tanks to force out water, again make the submarine buoyant, and cause it to rise to the surface and float.
In practice, when a submarine surfaces, it doesn't use a lot of air from its high pressure air tanks to "blow the ballast tanks" because it takes a long time to pump up the high pressure air tanks again. What happens is that all the ballast tanks are given a "good shot" of high-pressure air (a few seconds), and then the planes are used in conjunction with the screw (which some call a propellor) to actually drive a submarine to the surface. Once there, something called a low-pressure blower system can be used to finish blowing the ballast tanks (while the high-pressure air compressors are running to pump the high-pressure air tanks back up).
138⟩ What is railroad track ballast?
That being said railroad track ballast is the cover for the subgrade. Ballast has several functions:
* a) It enables water to drain from the track
* b) It assists in helping control the thermal expansion of continues welded rail
* c) As a train passes the rails, it supports the train
* d) It distributes the weight of the train from the track structure to the sub grade
* e) Maintains a smooth running surface for the train to run on
As ballast becomes contaminated with other materials, it looses its ability to do some or all of these jobs.
139⟩ What are the advantages of powder metallurgy?
Power metallurgy is much faster production while holding closer sizes.
140⟩ Who built the Trans Alaska pipelene?
The pipe was constructed in six sections by five different contractors employing 21,000 people at the peak of work.
