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Mechanical Engineering
Mechanical Engineering is a branch of engineering that encompasses the generation and application of heat and mechanical power and the design, production, and use of machines and tools. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid mechanics, strength of materials, materials science, electronics, and mathematics.
10,989 Questions
A force of 1000n is exerted on piston 1 what will be exerted on piston 2?
If this is about a hydraulic system, same pressure acts through out the fluid.
Take,
A = cross sectional area (area normal to force) of piston 1
B = "" "" "" of piston 2
F2 = Force on 2nd piston
So, pressure = 1000/A = F/B
Therefore, F = (1000 X B/A ) N
(The force depends on the area ratio)
How eliminate surge phenomenon in spring?
Surge in springs is avoided by the following methods.
(i) The spring is designed in such a way that the natural frequency of the spring is 15 to 20 times the frequency of excitation of the external force. This prevents the resonance condition to occur.
(ii) The spring is provided with friction dampers on central coils. This prevents propagation of surge wave.
(iii) A spring made of stranded wire reduces hte surge.
How long will it take metal to reach the equivalent ambient temperature?
The answer depends on many factors:
- type of metal and its specific heat capacity
- quantity of metal in question
- current metal temperature
- current ambient temperature
Depending on these factors the answer could range from mere moments to hours or even days.
What is a RFTBE weld neck flange I have never seen RFTBE related to flange description before?
Raised Face Through Bolt End.
What is whipping in connecting rod?
due to the inertia effect of the reciprocating masses, connecting rod suffers some perpendicular stress, which causes rapid vibrations at high speed, and tends to produce peculiar motion, this is called whipping action , it also causes bending action in connecting rod.
Prove that poissons' ratio is 0.5?
since k=E/3(1-2n):
where k=bulk modulus
and n=poision's ratio
it can be seen that value of poision's ratio can't be smaller than 0.5 in order to keep k be +ve.hence poision's ratio is 0.5
What is the difference between torsion and twisting of shaft?
Torque
Torque is experienced in simple day to day activities such as turning a doorknob, fastening a bolt, turning the steering wheel, paddling a bicycle, or even turning your head. It must be noticed that in each and every one of these activities, the movements are circular or rotational movements. It can be shown that in every movement where a change in the angular momentum occurs, there is always a torque acting upon the object. A torque is generated by a pair of forces, similar in magnitude and opposite in direction and parallel to each other. These two forces are separated by a finite distance. In physics, the term moment also has the same meaning as torque. Torque is defined as the tendency of a force to rotate an object about an axis, a fulcrum or a pivot. A torque can also be provided using a single force acting at a distance r from the axis of rotation. The torque of such a system is equal to the cross product of the applied force and r. Torque is mathematically defined as the rate of change of angular momentum of and object. It can be clearly seen that this is compatible with the force - linear momentum relationship in linear movements. The torque is also equal to the product of the moment of inertia and the angular acceleration. Torque is a vector with the direction determined by the cross product of the force and distance. It is perpendicular to the plane of rotation.
Torsion
Torsion is experienced in day to day activities such as tightening a screw or twisting a cloth. Torsion is the deformation of objects due to a pair of equal and opposite torques. There can be torsion even if the net torque of the system is zero. If a single torque is applied to a fixed object, which cannot rotate in any direction freely there will always be another torque generated by the reactive forces on the fixed point. The amount of twisting due to an applied torque depends on the torsional rigidity of the system. The twist angle and the torque hold a linear relationship, where the torsional rigidity is the proportionality constant.
What is the difference between torque and torsion?
- Torque is a measureable concept, whereas torsion is a concept, which is mathematically projected by the shear stress or the twist angle.
- Torque requires at least one force and torsion requires at least two forces to happen.
- Torque depends only on the magnitude, directions and the separation of the forces applied, while torsion depends on the torque, the type of material and the shape of the object.
What is the material poisson ratio of Epdm?
Depends on the hardness of the formulation. Poisson's ratio depends mainly on the bulk modulus and slightly on the Youngs modulus at very low strains for the subject compound. If the Youngs modulus lies between 0.92 and 9.40MN/m², Poisson's ratio lies between 0.49930 and 0.49993.
What steel has a strength of 500 MPa?
Most stainless steels have a strenght of at least 500 MPa. Most alloy steels also have that strength.
Yes, but the etching solution and type to be used depends on the material
Is the gain same for same system in open loop and closed loop?
A: DEFINITELY NOT Open loop is defined as no feedback. any kind of negative feedback will reduce the gain
Is axial flow gas turbine compressor is self propelled or some external power is provided?
no, it`s not , it also require some external power.
Difference between basic size and nominal size of an assembly?
on the basis of nominal diameter with tolerances is called nominal size, while required size is called basic size
The storage and loss modulus in visco-elastic solids measure the stored energy, representing the elastic portion, and the energy dissipated as heat, representing the viscous portion
Storage:
E' = (ε0 / σo ) Cos (δ)
Loss:
E" = (ε0 / σo ) Sin (δ)
What are the advantages of concurrent engineering?
Manufacturing Personnel are able to identify production capabilities and
capacities .They have thus the opportunity to inform the design group about the
suitability of certain materials on the flipsides the designer would know the
suitability of certain designs in aiding in cost reduction and quality improvement in
production/assembly process.
Early opportunities for design or procurement of critical tooling, some of which
might have long lead times.
early consideration of the Technical Feasibility of a particular design or a portion
of a design. Again this can avoid serious problems during production.
What is the Difference between nominal and actual cooling capacity?
In general actual capacity is bit less than the nominal capacity of any form
How do you calculate the blank size in sheet metal?
The blank size of sheet metal can be calculated using the bend allowance. This number is based on the metal thickness and the tool radius in the brake.
What is the Pressure drop in glove valve?
You mean GLOBE valve and that would depend on the size of the valve and the maker
How volute casing functions in pump?
volute has an increasing flow area as it wraps around the impeller.So, when the pump is operating at BEP (best efficiency point) ,have to keep the flow velocity constant around the impeller. To achieve that function, the area increases so as to accept the additional flow exiting the impeller.
What is Transistor Controlled Ignition?
Instead of using a distributor to determine when each cylinder fires, the car's ECU uses camshaft and crankshaft position sensors, along with MAP/MAF and throttle position sensors to determine the optimum time to fire each cylinder for the most power/lowest emissions. As opposed to fixed advance (vacuum or centrifugal) employed in distributors. Transistor Controlled Ignition is commonly referred to as Coil On Plug (COP), Transistor Controlled Ignition is just marketing bumpf to make it sound awesome.
