Mechanical Engineering

In the bottoming cycle of cogeneration, low grade waste heat is used for 

In steam-injection system compression is achieved by

For minimizing knocking tendency in SI engine, where should the spark plug be located ?

A uniform bar lying in the x - direction is subjected to pure bending. Which one of the following tensors represents the strain variation when bending moment is about the z-axis (p, q and r constants)?

In the design of shafts made of ductile materials subjected to twisting moment and bendingmoment, the recommended theory of failure is

The desirable air velocity in the occupied zone for comfort for summer air-conditioners is in the range of

In a wormed geared pulley block, if the number of teeth on the worm wheel is doubled, then its velocity ratio is also doubled.

A simply supported beam with width 'b' and depth ‟d‟ carries a central load W and undergoes deflection δ at the centre. If the width and depth are interchanged, the deflection at the centre of the beam would attain the value

The elements of most concern in regard to pollution caused by engines are

Match the List-1 (Types of shaper) with List-II (Related parameters):
List-I
A. Hydraulic shaper
B. Mechanical shaper
C. Standard shaper
D. Vertical shaper
List-II
1. Slotted link mechanism
2. Rotary worktable
3. Oil pressure
4. Worktable has horizontal and vertical movements

The relationship for cutting tool life is

Shape of true stress-strain curve for a material depends on

Two sheets of same material but different thickness can be butt welded by

When a system reaches the state of equilibrium, the following property assumes its maximum value

Hydrogen is used in electrolux refrigeration system so as to ....... the rate of evaporation ofthe liquid ammonia passing through the evaporator.

A 400 mm diameter shaft is rotating at 200 rpm in a bearing of length 120 mm. If the thickness of oil film is 1.5 mm and the dynamic viscosity of the oil is 0.7 Ns/m² determine:
(i) Torque required overcoming friction in bearing;
(ii) Power utilization in overcoming viscous resistance;

   A system comprising a single phase is called a

Negative slack occurs when

The process of cutting a flat sheet to the desired shape is known as

In which one of the following is a fly wheel generally employed?

The COP of a refrigerator working on reversed carnot cycle is 4. The ratio of highest absolute temperature is lowest absolute temperature is .

When plates are fastened by a rivet, the holes in the plates should be made by punching and reaming.

A length of 10 mm diameter steel wire is coiled to a close coiled helical spring having 8 coils of 75 mm mean diameter, and the spring has a stiffness K. If the same length of wire is coiled to 10 coils of 60 mm mean diameter, then the spring stiffness will be

If at the optimum in a linear programming problem, a dual variable corresponding to a particular primal constraint is zero, then it means that

[1996]

Silicon in cast iron

Match the List-I (Layout types) with List-Il (Layout characteristics):
List-l
A. Process layout
B. Product flow layout
C. Fixed position layout
D. Cellular layout

List-II 
1. inflexible to significant changes in product design.
2. Distinct part families and expanded worker training.
3. Low equipment utilization and high skill requirement.
4. Large work-in-process and increased material handling.

When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by

A beam is said to be in general stable and statically determinate for general loading when number of reaction components is

Thermal converter cannot reduce emission of

Which of the following theory is most suitable for brittle materials

Which of the following is true for centrifugal casting

Match List-I (Air-fuel ratio by mass) with List- II (Engine operation mode) and select correct answer using the codes given below the lists:

Mitre gears are used for

A sheet of metal is being cut along its length in a straight line such a cutting operation is called

The process which improves the machinability of steels, but lowers the hardness and tensile strength is

Consider the following statements:              

When two gears are meshing, the clearance is given by the  

1. Difference between dedendum of one gear and addendum of the mating gear.  

2. Difference between total and the working depth of a gear tooth.  

3. Distance between the bottom land of one gear and the top land of the mating gear.  

4. Difference between the radii of the base circle and the dedendum circle.  

Which of these statements are correct?    

In a vapour compression plant, if certain temperature differences are to be maintained in the evaporator and condenser in order to obtain the necessary heat transfer, then the evaporator saturation temperature must be:

The hydraulic mean depth or the hydraulic radius is the ratio of

All of followings are correct except: Inlet -valve mach index is dependent on

Built up edge is formed while machining

Strain energy is the

For viscous flow between two parallel plates, the pressure drop per unit length is equal to

A cast Steel slab of dimension 30 × 20 × 5 cm is poured horizontally using a side riser. The riser is cylindrical in shape with diameter and height, both equal to D. The freezing ratio of the mould is

[PI 2005]

The polar modulus for a hollow shaft of outer diameter (D) and inner diameter (d ) is

M/s. ABC & Co. is planning to use the most competitive manufacturing process to produce an ultramodern sports shoe. They can use a fully automatic robot-controlled plant with an investment of Rs. 100 million; alternately they can go in for a cellular manufacturing that has a fixed cost of Rs. 80 million. There is yet another choice of traditional manufacture that needs in investment of Rs. 75 million only. The fully automatic plant can turn out a shoe at a unit variable cost of Rs. 25 per unit, whereas the cellular and the job shop layout would lead to a variable cost of Rs. 40 and Rs. 50 respectively. The break even analysis shows that the break even quantities using automatic plant vs traditional plant are in the ratio of 1: 2. The per unit revenue used in the break even calculation is: 

In a boiler is mass of liquid water flow is 10 kgand mass of steam produced is 1 kg circulationratio is

A round rod of annealed bras 70-30 is being drawn from a diameter of 8 mm to a diameter of 4 mm at a speed of 0.8 m/s. (k = 895 MPa, n = 0.49)

Q.

The power required in this operation is

Tardiness is the measure of

The flow of fluid through a pipe is laminar when

Solid CO₂ is produced by

Which of the following are pure substance.
i.O₂ & N₂ mixture
ii. Moist Air
iii. Dry Air.

When the molten metal is poured in a mould, it may pass through the following items in sequence

The product of Young's modulus (E) and moment of inertia (I) is known as

Stoichiometric ratio is

A helical gear made of plain carbon steel has face width 10 times the normal module. If number of teeth on pinion and gear are 20 and 60 respectively, then what will be the wear strength of helical gear? (Assume m_n = 5, BHN = 200 & Ψ = 24^o)

Critical pressure of a liquid is the pressure

Fracture voids usually form at

The heating of a gas at constant pressure is governed by

A half nut is :

Pitching of a ship produces forces on the bearings

A rotor supported at A and B, carries two masses as shown in the given figure. The rotor is

The given figure shows a slider mechanism in which link 1 is fixed. The number of instantaneous centers would be

In an LPP if one of the decision variable is zero then the solution is

The vapour pressure over the concave surface is

In the calculation of induced shear stress in helical springs, the Wahl's correction factor is used to take care of 

The force resisting the outward movement of balls of the governor is known as

In which of the following are metal moulds used?       

The speed factor (speed ratio) of a Pelton turbine for its efficient operation lies in the range    

Consider the followings statements:
1. Sintering is a heating process used to increase.the strength and hardness of the compact powder.
2. Sintering temperature is approximately equal to three-fourth of melting temperature.
3. Vacuum sintering is employed for stainless steel and titanium.
Which of the above are correct?

Which of the following has threads at both ends?

Failure due to excessive deformation is controlled by

Which of the following statement is incorrect?

A copper rod 400 mm long is pulled in tension to a length of 401.2 mm by applying a tensile stress of 330 MPa. If the deformation is entirely elastic, the Young's Modulus of copper is

With the increase of percentage of carbon in the steel, which one of the following properties does increase? 

The continuity equation in differential form is

When is the greatest economy obtained in a regenerative feed heatingcycle? 

If u and v are the components of velocity in the x and y directions of a flow given by u - ax + by; v = cx + dy, then the condition to be satisfied is
 

 Which of the following aspect is not true regarding microscopic propertie s of thermodynamic system