Consider three identical items in parallel. What is the system reliability if each item has a reliability of 98%?

Answer:

0.05 J/K

Explanation:

Given data in question

heat (Q) = 10 J

temperature (T) = 200 K

to find out

the change in entropy of the system

Solution

we will solve this by the entropy change equation

i.e  ΔS = ΔQ/T           ...................1

put the value of heat Q and Temperature T in equation 1

ΔS is the enthalpy change and T is the temperature

so  ΔS = 10/200

ΔS = 0.05 J/K

Answer:

35°c

Explanation:

Given data in question

heat = 35 kw

work = 35 kw

temperature = 35°c

To find out

temperature of the system after this process

Solution

we know that first law of thermodynamics is Law of Conservation of Energy

i.e  energy can neither be created nor destroyed and it can be transferred from one form to another form

first law of thermodynamics is energy (∆E) is sum of heat (q) and work (w)

here we know

35 = 35 + m Cv ( T - t )

35-35 = m Cv ( T-t )

T = t

here T = final temperature

t = initial temperature

it show final temp is equal to initial temp

so we can say temp after process is 35°c

False it is External

Answer:

the heat loss from this insulated wire is less

Explanation:

Given data in question

diameter of cable (d)  =  20 mm

( K ) = 1 W/m-k

heat transfer coefficient (h) = 50 W/m²-K

To find out

the heat loss from this insulated wire

solution

we will find out thickness of wire

heat loss is depend on wire thickness also

we have given dia 20 mm

so radius will be d/2 = 20/ 2 = 10 mm

Now we find the critical thickness i.e.

critical thickness = K / heat transfer coefficient

critical thickness = 1 / 50 = 0.02 m i.e. 20 mm

now we can see that critical thickness is greater than radius 10 mm

so our rate of heat loss will be decreasing

so we can say our correct option is (a) less

Answer:

0.5 feet

Explanation:

it is given that the martin floats at draft of 23'6"

GM=1.5

The load is given as follows

1400 tons is loaded as 2 feet above keel

1400 tons-----kg----2 feet

final kg = [tex]\frac{final moment }{final dispacement}[/tex]

[tex]\frac{weight}{1400 kg}[/tex] =  [tex]\frac{kg}{2 feet}[/tex] =   [tex]\frac{moment of keel }{2800}[/tex]

final kg = [tex]\frac{2800}{1400}[/tex]=2 feet

final GM =2 feet-1.5 feet

=0.5 feet

Answer: False

Explanation: Sandwich materials are usually in composite material form which has a fabrication of two thin layers which are stiff in nature and have  light weighing and thick core .The construction is based on the ratio that is of stiffness to the weight .Therefore, the density of the material in the core is not high and are only connected with the skin layer through adhesive .So the given statement is false that sandwich materials typically use a high density core with non- structural cover plates.

Answer:500,551.02

Explanation:

Given

Initial enthaly of pump \left ( h_1\right )=500KJ/kg

Final  enthaly of pump \left ( h_2\right )=550KJ/kg

Final  enthaly of pump when efficiency is 100%=[tex]h_2^{'}[/tex]

Now pump efficiency is 98%

[tex]\eta [/tex]=[tex]\frac{h_2-h_1}{h_2^{'}-h_1}[/tex]

0.98=[tex]\frac{550-500}{h_2-500}[/tex]

[tex]h_2=551.02KJ/kg[/tex]

therefore initial and final enthalpy of pump for 100 % efficiency

initial=500KJ/kg

Final=551.02KJ/kg

Answer:

Explanation:

negative feedback control of the amplifier is achieved by applying output voltage signal back to inverting input terminal by feedback

transfer function is T=[tex]\frac{g}{1+Gh}[/tex]

where G=forward Path gain

H=negative feedback gain

here G=[tex]\frac{5}{S+3}[/tex]

H=10

T(S)=[tex]\frac{G}{1+GH}[/tex]

=[tex]\frac{5}{S+53}[/tex]

Answer:

0.025 m/sec

Explanation:

we have given m =0.25 kg

velocity=0.05 m/sec

radius =0.5 meter

the centrifugal force produced due to rotational motion

[tex]F_c=\frac{mv^2}{r}=\frac{0.25\times 0.05^2}{0.5}=0.00125 N[/tex]

now again using this equation for finding the final velocity

[tex]0.00125=\frac{mv_{final}^2}{r}=\frac{0.25v_{final}^2}{0.125}[/tex]

[tex]v_{final}=\sqrt{\frac{0.00125\times 0.125}{0.25}}=0.025\ m/sec[/tex]

so the final speed of mass spring will be 0.025 m/sec

Answer:

[tex]V=68.86ft^3[/tex]

Explanation:

[tex]T_1[/tex] =10°C,[tex]T_2[/tex] =93.33°C

Q=500 btu=527.58 KJ

[tex]P_1= 2atm[/tex]

If we assume that air is ideal gas   PV=mRT, ΔU=[tex]mC_v(T_2-T_1)[/tex]

Actually this is closed system so work will be zero.

Now fro first law

Q=ΔU=[tex]mC_v(T_2-T_1)[/tex]+W

⇒Q=[tex]mC_v(T_2-T_1)[/tex]

527.58 =[tex]m\times 0.71(200-50)[/tex]

m=4.9kg

 PV=mRT

[tex]200V=4.9\times 0.287\times (10+273)[/tex]

[tex]V=1.95m^3[/tex]                ([tex]V=1m^3=35.31ft^3[/tex])              

[tex]V=68.86ft^3[/tex]

Answer:

The most common type of pumps are Positive displacement and Non positive displacement pumps.

Explanation:

Pumps are two types:

     (A) Positive displacement pump

             (a)Gear pump

                      (1) Ge rotor pumps

                      (2)Internal gear pumps

                      (3)Lobe pumps

                      (4) External gear pumps

               (b)Piston pump

                       (1)Radial piston

                       (2)Axial piston

               (c)vane pump

        (B) Non positive displacement pump

             (a) Centrifugal pump

Answer:

969.68N

Explanation:

d₁=0.04 m      A₁=[tex]\frac{\pi d^2_{1}  }{4}[/tex]

[tex]A_{1} =\frac{\pi \times .04^2}{4}= 0.00125m^{2} \[/tex]

d₂=0.02 m      A₂=[tex]\frac{\pi d^2_{2}  }{4}[/tex]

[tex]A_{2} =\frac{\pi \times .02^2}{4}= 0.00031m^{2} \[/tex]

Q=1.2m³/min        Q=1.2/60=0.02m³/s

using continuity equation

Q₁=A₁v₁

v₁=Q₁/A₁=0.02/0.00125=16m/s

Q₂=A₂v₂

v₂=Q₂/A₂=0.02/0.00031=64.5m/s

[tex]F_{inlet}=\rho A_{1}v_1^{2}[/tex]

[tex]F_{inlet}=1000\times 0.00125\times16^{2}=320N[/tex]

[tex]F_{outlet}=\rho A_{2}v_2^{2}[/tex]

[tex]F_{outlet}=1000\times 0.00031\times64.5^{2}=1289.68N[/tex]

Force on the nozzle=F_{outlet}-F_{inlet}

= 1289.68-320

=969.68N

Answer:

Velocity component in x-direction [tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex].

Explanation:

   v=3xy+[tex]x^{2}[/tex]y

We know that for incompressible flow

   [tex]\frac{\partial u}{\partial x}+\frac{\partial v}{\partial y}=0[/tex]

[tex]\frac{\partial v}{\partial y}=3x+x^{2}[/tex]

So   [tex]\frac{\partial u}{\partial x}+3x+x^{2}=0[/tex]

[tex]\frac{\partial u}{\partial x}= -3x-x^{2}[/tex]

By integrate with respect to x,we will find

[tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex]+C

So the velocity component in x-direction [tex]u=-\frac{3}{2}x^2-\frac{1}{3}x^3[/tex].

Answer: The correct answer is Option d.

Explanation:

Ohm's law is defined as the law which gives us the relationship between voltage and current.

In electronics, the equation used to represent this law is:

[tex]E=IR[/tex]

where,

E = voltage of the circuit. The unit for this is Volts.

I = current of the circuit. The unit for this is Amperes

R = resistance of the circuit. The unit for this is Ohms.

Hence, the correct answer is Option d.

Answer:

True

Explanation:

For point in xz plane the stress tensor is given by[tex]\left[\begin{array}{ccc}Dx_{} &txz\\tzx&Dz\\\end{array}\right][/tex]

where Dx is the direct stress along x ; Dz is direct stress along z ;  tzx and txz are the  shear stress components

We know that the stress tensor matrix is symmetrical which means that tzx = txz  ( obtained by moment equlibrium )

thus we require only 1 independent component of shear stress to define the whole stress tensor at a point in 2D plane

Answer:

Heat transfer for a internally reversible process.

Explanation:

Internally reversible means that there is entropy generation ' with in ' the system.

Heat transfer of a process is considered to be reversible if it occurs because of any minute temperature difference between the surrounding and the system .  

Let us consider an example ,  

Transferring of the heat across the difference in  temperature of 0.0001 °C appears as  more reversible than for the difference in temperature of 100 °C .  

Hence ,  

By heating or cooling a system for a number of infinitesimally small steps , we can approximate a reversible process.

Answer:

b). false

Explanation:

Lean manufacturing

Lean manufacturing, a philosophy developed by Toyota Production System are means to eliminate wastes. They are defined as the techniques or management activities in eliminating wastes and increasing the efficiency inside an organisation.

    According to the concept of lean manufacturing, mainly seven types of wastes are identified. They are :

1. Transportation waste

2. Inventory waste

3. Over production

4. Waiting

5. Defects

6. Motion waste

7. Non utilized talent

All these waste affect greatly to the efficiency of an organisation and devalue its services.  Lean manufacturing advises to prevent  all these waste in order to increase the productivity.

       All the management activities and techniques used in lean manufacturing may be different according to the business application but they are all based on the same basic principle of removing wastes and errors and increase efficiency.

The different sectors that are benefiting from lean manufacturing methodology are

Healthcare

Hospitality

Food and Beverage

Government

Manufacturing

Lean manufacturing can be used in different sectors.

Answer:

Answer is c 0.500

Explanation:

[tex]SpecificGravity=\frac{\rho _{fluid}*g}{\rho _{water}*g}[/tex]

We know that [tex]\rho_{water}=62.42lb/ft^{3}[/tex]

Applying values we get

[tex]SpecificGravity=\frac{31.2}{62.4}=0.5[/tex]

Answer:

55.56%

Explanation:

Given data

Temprature of hot reservior =2000°c=2273k

Temprature of Cold reservior=25°c=298k

Power produced by engine=50MW

Heat rejected =40MW

we know that Effeciency(η) of heat engine=[tex]\frac{Work produced}{heat supplied}[/tex]

Also we know that

heat supplied[tex]\left ({Q_s} \right )=work produced{W}+Heat rejected{Q_r}[/tex]

Q_s=50+40=90MW

η=[tex]\frac{W}{Q_s}[/tex]

η=[tex]\frac{50}{90}[/tex]

η=55.55%

Answer: a)True

Explanation: Takt time is defined as the average time difference between  the production of the two consecutive unit of goods by the manufacturer and this rate is matched with the demand of the customer. This is the time which is calculated to find the acceptable time for which the goods unit must be produced  by the factory to meet the needs of the customer. Therefore , the statement is true that takt time is the rate at which a factory must produce to satisfy the customer's demand.

Answer and explanation:

Deformation means change in position plastic deformation mainly cause due to motion of dislocation

THERE ARE MAINLY TWO MECHANISM BY WHICH PLASTIC DEFORMATION TAKES PLACE

SLIP : slip is a process of sliding of blocks over one  another along the planes  these planes are called slip planes slip takes place when the shear stress exceeds than the critical value of stress distance between the slip planes are called slip lines the resistance for slip plane is very less as compared to any other planes the slip plane is the plane has very high density

Answer:

Tolerance is important for the very fact that providing proper tolerances ensures proper fittings of different parts.                                            

Explanation:

Tolerance and dimensioning is an important link between manufacturing and engineering.

Tolerance optimization leads to high cost of machined part to be produced and also provides good quality product. Whereas loose tolerance means reduction in cost but poor quality product. hence it is very important and critical to provide the right tolerance while designing a product.

                               Tolerance also influence what type of production processes to be selected by the process planners. The optimization of the tolerances during the design phase has a positive impact on the results coming out of the manufacturing processes.

                                Providing proper tolerances ensures that the parts will fit properly.

Therefore, providing proper tolerances, the engineers shares the responsibility to manufacture the parts correctly.

Explanation:

A solid state laser contains a cavity like structure fitted with spherical mirrors or plane mirrors at the end filled with a rigidly bonded crystal. It uses solid as the medium. It uses glass or crystalline materials.

    It is known that active medium used for this type of laser is a solid material. This lasers are pumped optically by means of a light source which is used as a source of energy for the laser. The solid materials gets excited by absorbing energy in the form of light from the light source. Here the pumping source is light energy.  

Answer:

explained below

Explanation:

An Abandoned well is well no longer in use or in such a state of despair that ground water can no longer be pumped out of it in useable quantity.

Following are few reasons for abandoning wells:

1. When the level ground water level falls down the well becomes redundant. And in recent times the ground water level has fallen to appreciable magnitude.

2. Wells represent potential conduits or pathways for surface contaminants to reach ground water supply.The ground water contamination at your well is likely to show up in municipal water supply.

3. Moreover, if the well is unused it  can cause physical hazard to people and animals living nearby. As these well grow vegetation around them thus hiding their hole.  

Answer:

[tex]\eta[/tex]=0.60

Explanation:

Given :Take [tex]\gamma[/tex]=1.4 for air

      [tex]P_1=100 KPa  ,T_1=300K[/tex]

  [tex]\frac{V_1}{V_2}[/tex]=r ⇒ r=16

As we know that  

   [tex]T_2=T_1(r^{\gamma-1})[/tex]

So [tex]T_2=300\times 16^{\gamma-1}[/tex]

  [tex]T_2[/tex]=909.42K

Now find the cut off ration [tex]\rho[/tex]

      [tex]\rho=\frac{V_3}{V_2}[/tex]  

         [tex]\frac{V_3}{V_2}=\frac{T_3}{T_2}[/tex]

[tex]\rho=\frac{2031}{909.42}[/tex]

 [tex]\rho=2.23[/tex]

So efficiency of diesel engine

[tex]\eta =1-\dfrac{\rho^\gamma-1}{\gamma\times r^{\gamma-1}(\rho-1)}[/tex]

Now by putting the all values

[tex]\eta =1-\dfrac{2.23^{1.4}-1}{1.4\times 16^{1.4-1}(2.23-1)}[/tex]

So [tex]\eta[/tex]=0.60

So the efficiency of diesel engine=0.60

Answer:

Out of the four options provided, the most accurate answer is

option b) increase in the buoyancy force

Explanation:

Natural convection is a process in which thermal expansion of fluid takes place naturally due to natural buoyancy resulting in motion of fluid when it is heated.

Differences in densities result in buoyancy and natural convection depends on buoyancy force. Also higher air temperatures are found at lower densities which is found at the outlets of the channels and the larger the channel size, the larger is the buoyancy force (as the density difference will be higher).

Answer:

the flow rate of the oil is 2.5 m³/s

Explanation:

Given data

relative density (S) = 0.8

diameter (d1) = 60 mm = 0.06 m

diameter (d2) = 35 mm = 0.035 m

height (h) = 22 mm = 0.022 m

discharge coefficient (Cd) = 0.98

To find out

the flow rate of the oil

solution

we know the formula for rate of flow i.e.

flow rate = Cd a1 a2 [tex]\sqrt{2 g n }[/tex] /  [tex]\sqrt{a1^{2} a2^{2} }[/tex]    ...............1

here first we find area a1 and a2 i.e.

a1 = ( [tex]\pi[/tex] /4 ) × d² = ( [tex]\pi[/tex] /4 ) × 0.06² = 0.002827 m²

a2 = ( [tex]\pi[/tex] /4 ) × d² = ( [tex]\pi[/tex] /4 ) × 0.035² = 0.000962 m²

and now we find n = (density of mercury / density of oil)  - 1 × h

n = ((13.56 / 0.8)  - 1) × 0.022 = 0.3509

put all these value in equation 1

flow rate = Cd a1 a2 [tex]\sqrt{2 g n }[/tex] / [tex]\sqrt{a1^{2} a2^{2} }[/tex] 

flow rate = 0.98× 0.002827× 0.000962 [tex]\sqrt{2*9.81*0.3509}[/tex] / [tex]\sqrt{0.002827^{2} 0.000962^{2} }[/tex]

flow rate = 2.571386 m³/s

Answer:

0.1 J/K

Explanation:

entropy change equation is as followed:

[tex]\Delta S=\frac{\Delta Q}{T}[/tex]

where ΔS=entropy change

          Q=Heat transfer

          T= temperature

[tex]\Delta S=\frac{\Delta Q}{T}[/tex]

[tex]\Delta S=\frac{30}{300}[/tex]

[tex]\Delta S=0.1 J/K[/tex]

hence the change in entropy of system which is [tex]\Delta S[/tex]is equal to 0.1 J/K

Answer:  (1) heat power and convection

                (3)radiation

Explanation: Heat can be transferred in many different ways such as conduction,radiation form and convection etc.

Convection is a method of transferring of the heat from a particular surface by the help of fluids .E.g.- air

Radiation is the method of transfer of heat by the emission or absorption process in the other surface.E.g.- earth getting warm due to sun.

Therefore the answer to the question is option (1) and (3).

The mechanical dynamometer is an instrument used to measure forces or to calculate the weight of objects. The traditional dynamometer, invented by Isaac Newton, bases its operation on the stretching of a spring that follows the law of elasticity of Hooke in the measurement range. Like a scale with elastic spring, it is a spring scale, but it should not be confused with a scale of saucers (instrument used to compare masses).

These instruments consist of a spring, generally contained in a cylinder that in turn can be inserted into another cylinder. The device has two hooks or rings, one at each end. The dynamometers have a scale marked on the hollow cylinder that surrounds the spring. When hanging weights or exerting a force on the outer hook, the cursor of that end moves on the external scale, indicating the value of the force.

The dynamometer works thanks to a spring or spiral that has inside, which can be lengthened when a force is applied on it. A point or indicator usually shows, in parallel, the force.