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Mechanical Engineering

IOE Syllabus Latest Questions

Engineering Pidit
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Make a complete orthographic draawing of a solid cut by the plane as in the figure.

I want a complete solution to this drawing’s question. The question is about Surface development. And I felt a bit confused since the slicing is done on the top view. Please provide me with its true shape as well.

1st semdrawingdrawing iengineering drawingengineering drawing iexam pidit
  1. Sunil sharma

    yo question le ta exam maa pasina nikale thiyo πŸ˜‚

    yo question le ta exam maa pasina nikale thiyo πŸ˜‚

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Aastha_tandukar
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heat transferthermodynamics
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    sonal_shahi Beginner

    First law of thermodynamics states that during any cycle that a system undergoes, the cyclic integral of the heat equals cyclic integrals of the work. The first law, however, places no restriction on the direction of flow of heat and work. A cycle in which a given amount of heat is transferred fromRead more

    First law of thermodynamics states that during any cycle that a system undergoes, the cyclic integral of the heat equals cyclic integrals of the work. The first law, however, places no restriction on the direction of flow of heat and work. A cycle in which a given amount of heat is transferred from the system and an equal amount of work is done on the system satisfies the first law just as well as a cyclic in which the flow of heat and work are reversed. However, we know from our experience that a proposed cycle that does not violate the first law does not ensure that the cycle will actually occur. It is a kind of experimental evidence that led to the formulation of the second law of thermodynamics. Thus a cycle will occur only if both the first law and second law of thermodynamics are satisfied.

    Consider a hot water glass left in a cooler room that eventually cools off. This process satisfies the first law of thermodynamics as the amount of energy lost by hot water equals amount of heat gained by the surroundings. If we consider a reverse process, i.e., hot water getting even hotter in a cooler room as a result of heat transfer from the room air. It is obvious that this process never takes place. Furthermore, this process does not violet first law of thermodynamics as long as amount heat lost by air equals the amount of heat gained by hot water

    Gasoline isΒ  used as a car drives up hill, but the fuel in gasoline tank cannot be restored to it’s original level when car coasts down the hill. However, this process as well does not violate first law of thermodynamics.

    These arguments clarify that processes proceed in a certain directions and not in the reverse direction. The first law of thermodynamics places no restriction on the direction of a processes and satisfying the first law of thermodynamics does not ensure that the process can actually occur. This inadequacy of the first law of thermodynamics to identify whether a process can take place in remedied by introducing another general principle, called second law of thermodynamics. The reversed processed discussed in above examples violet the second law of thermodynamics.

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sonal_shahi
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heat transferthermodynamics
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    Aastha_tandukar Beginner

    Similarities i) Work transfer and heat transfer are transient phenomena. Systems do not possess heat or work. Whenever systems undergo changes of state, they can cross the system boundary. ii) They are observed only at the boundaries of the system. iii) They are path functions and inexact differentiRead more

    Similarities

    i) Work transfer and heat transfer are transient phenomena. Systems do not possess heat or work. Whenever systems undergo changes of state, they can cross the system boundary.

    ii) They are observed only at the boundaries of the system.

    iii) They are path functions and inexact differentials.

    iv) They are not a property of a system.

     

    Differences:

    i) Work transfer is defined as the way by which a system may exchange energy with its surroundings. Work is said to be transferred if a certain system is displaced by a force in the direction of it.

    Heat transfer is defined as the form of energy that is transferred across the boundary of a system at a given temperature to another system or the surrounding at a lower temperature by virtue of the temperature difference between the two systems.

    ii) In thermodynamics, the work done by the system is considered as positive work transfer and work done on the system is considered as negative work transfer whereas heat transferred to a system is considered as positive heat transfer and heat transfer from a system is considered as negative heat transfer.

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Aastha_tandukar
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heat transferthermodynamics
  1. sonal_shahi Beginner

    The perpetual motion was originally conceived as a purely mechanical contrivance when once set in motion would continue to run forever. Such a machine would be merely a curiosity of no practical value and we know that the presence of friction makes it impossible. One would be of immense value is a mRead more

    The perpetual motion was originally conceived as a purely mechanical contrivance when once set in motion would continue to run forever. Such a machine would be merely a curiosity of no practical value and we know that the presence of friction makes it impossible. One would be of immense value is a machine producing a continuous supply of work without absorbing energy from the surroundings, such as a machine is called a perpetual motion machine of the first kind.

    It is always possible to devise a machine to deliver a limited quantity of work without requiring a source of energy in the surroundings. For example, a gas compressed behind a piston will expand and do work at the expense of the internal work of the gas. Such a device cannot produce work continuously, however, for this to be achieved the machine must be capable of undergoing a succession of cyclic processes. An equation  ΣδQ=ΣδW states that if a net amount of heat is not supplied by the surroundings during a cycle, no net amount of work can be delivered by the system. Hence, the first law of thermodynamics implies that a perpetual motion machine of the first kind is impossible.

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kirpathapa
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heat transferthermodynamics
  1. lidiya thapa Beginner

    Merits of a two stroke engine over four stroke engine i) A two stroke engine has twice the number of power stroke than a four stroke engine at the same speed. Hence theoretically a two stroke engine develops double the power per cubic meter of the swept volume than the four stroke engine. ii) The weRead more

    Merits of a two stroke engine over four stroke engine

    i) A two stroke engine has twice the number of power stroke than a four stroke engine at the same speed. Hence theoretically a two stroke engine develops double the power per cubic meter of the swept volume than the four stroke engine.

    ii) The weight of two stroke engine is less than four stroke engine because of lighter flywheel due to more uniform torque on crankshaft.

    iii) The scavenging is more complete in low -speed two stroke engines, since exhaust gases are not left in the clearance volume as in the four stroke engine.

    iv) Since there are only two stroke in the cycle, the work required to overcome the friction and the exhaust strokes is saved.

    v) Since there are no mechanical valves and valve gears, construction of two strokes engine is simple which reduces its initial costs.

    vi) A two stroke engine can be easily reversed by a simple reversing gear mechanism.

    vii) A two stroke engine can be easily started than a four stroke engine.

    viii) A two stroke engine occupies less space.

    ix) A lighter foundation will be sufficient for two stroke engine.

    x) A two stroke engine has less maintenance cost since it requires only few parts.

    Demerits of two stroke engine compared with four stroke engine

    i) Since the firing takes place in every revolution, the time available for cooling will be less than in a four stroke engine.

    ii) Incomplete scavenging results in mixing of exhaust gases with the fresh charge which will dilute it, hence lesser power output.

    iii) Since the transfer port is kept open only during a short period, less quantity of the charge will be admitted into the cylinder which will reduce the power output.

    iv) Since both the exhaust and the transfer port are kept open during the same period, there is possibility of escaping of the fresh charge through exhaust port which will reduce thermal efficiency.

    v) For a given stroke and clearance volume, the effective compression stroke is less in a two stroke engine than in a four stroke engine.

    vi) In a crankcase compressed type of two stroke engine, the volume of charge down in the crankcase is less due to the reduction in the crankcase volume because of rotating parts.

    vii) A fan scavenged two stroke engine has less mechanical efficiency since some power is required to run the scavenged fan.

    viii) A two stroke engine needs better cooling arrangements because of high operating temperature.

    ix) A two stroke engine consumes more lubricating oil.

    x) The exhaust in a two stroke engine is noisy due to sudden release of the burnt gases.

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Aastha_tandukar
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heat transferthermodynamics
  1. sonal_shahi Beginner

    The characteristics of steady state steady flow process are; i) A steady state process is defined as a process during which a fluid flows throughΒ  a control volume steadily. ii) At a steady state of a system, any thermodynamic property will have a fixed value at a particular location and will not alRead more

    The characteristics of steady state steady flow process are;

    i) A steady state process is defined as a process during which a fluid flows throughΒ  a control volume steadily.

    ii) At a steady state of a system, any thermodynamic property will have a fixed value at a particular location and will not alter with time. Therefore, volume, mass, and total energy content of the control volume remain constant during a steady state process.

    iii) During steady state process, no intensive or extensive properties within the control volume change with time.

    iv) The boundary work transfer is zero for steady state system and the total mass or energy entering a control volume must be equals total mass or energy leaving it.

    v) The fluid properties at an inlet or an outlet remain constant during a steady state process. The properties may be different at different inlets and outlets. They might vary over the crossΒ  section of an inlet or an outlet. However, all properties including velocity and elevation must remain constant with time at a fixed point at an inlet or an outlet. It follows that mass flow rate of fluid at an opening must remain constant during a steady state process.

    vi) The fluid properties at an opening are usually considered to be uniformed over the cross section. Thus, theΒ  fluid properties at an inlet or an outlet may be specified by the average single values.

    vii) The heat and work interactions between a steady state process and its surroundings do not change with time. Hence, power delivered by a system remains constant during aΒ  steady state process.

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sonal_shahi
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environmentsocietytechnology
  1. Aastha_tandukar Beginner

    I am agreeing with that statement β€œtechnology can control price because of: i) Automation Increase in the production rate at low price with the help of modern tools like automation, management techniques etc. ii) Improved speed The advancement of technology allows professionals to share informationRead more

    I am agreeing with that statement β€œtechnology can control price because of:

    i) Automation

    Increase in the production rate at low price with the help of modern tools like automation, management techniques etc.

    ii) Improved speed

    The advancement of technology allows professionals to share information quickly and securely. This saves time, allowing for decision to be made faster and projects to be completed earlier.

    iii) More consumption of goods due to reduction in price

    According to supply-demand chain, low price due to more consumption. For example, electronic goods are cheaper now than yesterday.

    iv) Lessen mistake and errors

    Manufacturing cost shouldn’t be just above the finished product. If the product is faulty, this will also be a liability to the company. we have to deal with the cost of repairs. With new technology, it is possible to lessen mistakes and errors. In effect, it can lessen the number of products returned from the market. It also makes the customers happy, improving the overall reputation of the company.

    v) Lessen energy cost

    Green and efficient technology is now in demand. And it is in demand for good reasons. It performs the same amount of work for a business but also saves the environment in the process. For example the technology utilized by business to save energy is motion sensor switches. This means that an area will not light up unless there’s someone moving in the room.

    vi) Reduce the need of manpower

    Technological advancement can help give companies the chance to operate with a lower number of employees. If we look at car companies, for instance, they manufacture mostly with the help of machines with just a few technicians on standby to supervise if something goes wrong with the machines. That reduce the cost of the product

    vii) Productivity monitoring

    Productivity monitoring is just as important as the actual manufacturing process. New technology can help companies check if their production process is lagging. And, if there is an area where it needs improvement, it is easier to provide corrections and adjustments.

    For examples;

    Online shopping and payment system can reduce cost of clothes, electronic products etc., recharging sim card through online banking we get 2 percent benefit, High technology instrument help to carry out heavy construction work with short period of time that help to reduce construction cost.

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lidiya thapa
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fluid mechanicsorificemeterventurimeter
  1. kirpathapa Beginner

    The main differences between a venturimeter and orifice meter are: i) The venturimeter can be used for measuring the flow rates of all incompressible flows; whereas orifice meters are generally used for measuring flow rates of liquids. ii) Venturimeter is installed in pipeline only and flow continueRead more

    The main differences between a venturimeter and orifice meter are:

    i) The venturimeter can be used for measuring the flow rates of all incompressible flows; whereas orifice meters are generally used for measuring flow rates of liquids.

    ii) Venturimeter is installed in pipeline only and flow continues through the pipeline. In orifice meter, the entire potential energy is converted to kinetic energy and jet discharges freely into open atmosphere.

    iii) In venturimeter, the flow velocity is measured by noting the pressure difference between the inlet and throat of venturimeter, whereas in the orifice meter, the discharge velocity is measured by using pilot-tube or by trajectory method.

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Aastha_tandukar
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environmentsocietytechnology
  1. sonal_shahi Beginner

    The definition of technology is science or knowledge put into practical use to solve problems or invent useful tools. It is an application of science to solve a problem. Technology refers to the practical application of scientific knowledge for a purpose. it also includes the capability and skills rRead more

    The definition of technology is science or knowledge put into practical use to solve problems or invent useful tools. It is an application of science to solve a problem. Technology refers to the practical application of scientific knowledge for a purpose. it also includes the capability and skills required to apply the knowledge.

    There is a revolution in civil engineering happening due to technology. From drones to innovative construction materials, be on the looked for how technology will influence, impact and improve the civil engineering industry in twenty first century.

    In recent decay, the most one benefit from technology taken by a civil engineer is software tool in design part.

    Software packages are to the civil engineers what a towel is to a mason. In short, a civil engineer, through a mathematical model, analyze the behavior of construction materials, from the result of these analysis he or she can select the appropriate material and their combination for an efficient design. Software packages streamline these processes, allowing the engineer to do fast and accurate computation using different mathematical model and output them in a human-friendly graphical representation and effectively easing cross-disciplinary collaboration. A design process that could have taken years now could be reduced to a couple of weeks.

    Similarly like design part, the benefit of technology taken by civil engineer in other area are described below.

    i) More efficient daily operations

    In the part, construction companies faced the challenge of creating and sharing design information in real time. Designers and other professional would have to manually draw up sketches, project outlines and illustration. They would then have to send the sketches to relevant personnel and customers for review and approval.

    With construction technology, project managers can use software to co-ordinate projects, share digital sketches and receive feedback in real time. In this way, the daily operations of construction companies large and small are improving significantly.

    Construction technology also allows users to co-ordinate information across departments and with their clients. This results in a less costly and more streamlined daily operational model, with reduced changes orders and miscommunication.

    ii) Smarter and more durable structures

    Construction technologies produce smarter and more durable structures in two main ways:

    a) By designing better from scratch.

    b) By retrofitting existing structures for increased durability

    iii) Use of better tools

    Implementing construction technology is all about taking advantage of the best tools on the market today, and using them to create better work. Whether it’s using 3D imaging to generate more interactive models, laser scanning to facilitate efficient renovations or estimating systems that allow you to reduce costs, there is no shortage of platforms to improve your business.

    iv) Better client services

    For many years, the construction industry has had the challenge of communicating information efficiently to clients; owners would have to frequently visit the construction site to see how their project was proceeding and to ensure high standards of quality.

    v) Innovation

    Much of the innovation in the construction industry is being driven by technological advancements and with new software features added to platforms on a frequent basis, construction professionals are constantly presented with new opportunities for growth.

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