What are the major limitations of melt spinning method? a)-good for limited alloys and limited shapes b)-good for limited shapes, high cost c)-good for limited thickness and limited shapes d)-high cost, high energy consumption

Answer: D) Nozzle gimbals

Explanation: Igniters are present for the ignition power in the segmented solid rocket, liners are the basic requirement in the engine of the rocket,O-rings are also a general part of the segmented solid rocket .So, these are the general purpose parts of the segmented solid rocket but nozzle gimbals are the special units of the rocket as they provide improved thrust in various direction in accordance with the rocket.So, option (d) is the correct option.

Answer:

D. Nozzle gimbals

Explanation:

Segmented solid rockets require the special component, nozzle gimbals.

Answer:

explained

Explanation:

Gear is a  mechanical components designed for transfer of torque or power from one shaft to the other. Gear designing is a costly affair. The configuration and geometry of gears are such that its designing is tedious task. A lot of precision is required to design a gear. This is why factor of safety of gears are always kept higher.

The higher factor of safety accounts for durability of gears. Gears once made can used for about 200 hundred years. The wear and tear are less and the failure of gears is avoided. And hence whole machine failure can be avoided.  

Answer:

the answer is false solid rockets can experience significant 2 phase flow

Answer Explanation :

We know that entropy is the measure of molecular randomness it is denoted by S It is a thermodynamic property of gas it is an extensive property means its depend on the mass of the the system and specific entropy is defined as the entropy per unit mass its unit is KJ/kg.k

by using standard table the specific entropy for the subcooled liquid is 1.057 KJ/kg.k standard table is used for knowing the specific entropy of different liquid and gaes

Answer:

Clausius inequality is defined as, it applies in the cycle of real engine and there is negative entropy change. When the entropy given in the cycle during the environment is larger than entropy transferred into heat engine from hot reservoir. As, entropy of reversible system are zero.

Clausius Inequality is defined as:

[tex]R_2-R_1> \oint_{T_1}^{T_2}\frac{dQ}{T}[/tex]

Where R1 and R2 are not be equal.

Answer:

f = 628.32 lb

t = 2513.28 lb-inc

Explanation:

given data:

θ = 45°

outside radius = 6 inch

inside radius = 4 inch

coefficient of friction = 0.4

max pressure = 100 psi

a) determine force required for applying one pad

f =    [tex] \frac{\theta }{360}* 2\pi *p_{max}*r_{i}(r_{o}-r_{i})[/tex]

f = [tex] \frac{45 }{360}* 2\pi *100*4(6-4)[/tex]

f = 628.32 lb

b) torque capacity (t)

t = [tex]\mu *f*r_{average}^{}[/tex]

t = 0.4 *628.32*5

torque = 1256.64 lb-inc

for both pad = 2 * 1256.64 =2513.28 lb-inc

Answer:

Explanation:

it is given that diameter = 8.6 cm

[tex]radius =\frac{8.6}{2}=4.3\ cm=4.3\times 10^{-2}\ m[/tex]

current =2.7 ampere

number of turns = 15

[tex]area =\pi r^2=3.14\times \left ( 4.3\times 10^{-2} \right )^{2}=0.005806 m^{2}[/tex]

magnetic field =0.56 T

maximum torque= BINASINΘ  for maximum torque sinΘ=1

so maximum torque==0.56×2.7×0.005806×15=0.13174 Nm

Answer: Potential flow states about the velocity field considering it as gradient of scalar function such as the velocity potential. It is considered same as irrotational flow.

Explanation:In the study of fluid dynamics , potential flow is stated as the term for describing about the velocity field taking it as the gradient of a scalar function. Therefore, potential flow is stated by an irrotational velocity field  and there is a irrotation because of the curl of the gradient of scalar quantity is zero.Potential flow is considered same as the irrotational flow that is the particles in the fluids that do not rotate.

Answer:

Hot tear casting is the discontinuity or failures occurs during cooling or solidification phase in casting process. It is also known as hot crack

Explanation:

In case when the casting is of weak metal, when it is hot and casted, during the process residual stresses cause failures or discontinuity in casting as it cools resulting in hot tears i,e., material casted is partly liquid and partly solid.

Preventive measures:

Given:

Let the speed of sound be represented by 'v' then

v ∝ [tex]\sqrt{T}[/tex]              (1)

[tex]v_{1}[/tex] = 349 m/s

[tex]v_{2}[/tex] = 340 m/s

[tex]T_{1}[/tex] = 20°C = 273+20 = 293 K

Formulae used:

1)  °C = K + 273

2) K = °C - 273

3) °F = 1.8°C + 32

4) °R = °F + 459.67

Solution:

From eqn (1),

[tex]\frac{v_{1}}{v_{2}} = \sqrt{\frac{T_{1}}{T_{2}}}[/tex]

[tex]T_{2}[/tex] = [tex]T_{2} = (\frac{v_{2}}{v_{1}})^{2}T_{1}[/tex]

[tex]T_{2} = (\frac{340}{349})^{2}{293}[/tex] = 278.08 K

Now, Usinf formula (1), (2), (3) and (4) respectively, we get

1) T = 293 K

2) T = 293 -278.8 = 5.08°C

3) T = 1.8(5.08) + 32=41.14°F

4) T = 41.14 + 459.67 = 500.81°R

Answer: b)All substances emit radiation

Explanation: This is a universal statement that all bodies emit radiations . The radiations are usually in the form of electromagnetic radiations that are being emitted in accordance with temperature that varies from body to body.Even human bodies along with any other body emit radiations These radiations are absorbed by the black body.Therefore the correct option is option(b).

Answer:

The condition of very system can be identified by some physical characteristics of the system known as Thermodynamic Property of the system. For example, pressure, temperature, volume, etc.

Explanation:

Thermodynamic properties are nothing but the physical characteristics of any body by which the physical condition of the body can be described. properties describes the different states of a system. They are macroscopic.

               Properties are of two types ---

Intensive property

Extensive property

Intensive Property : Those properties of a system which does not depend upon mass of the system are known Intensive property.

                               For example, pressure, temperature, density,specific volume, etc

Extensive Property : Properties that depends on the mass oh the system is called Extensive properties.

                               For example, energy, volume, etc.

Answer: (c)Allotropy

Explanation: Allotropy is defined as the feature of the material to exist in different chemical forms or state while being in the same physical state. So, allotropy responsible for maintenance of the crystalline lattices during the temperature changes and does not alter the physical state of it. It helps elements to exist in different forms by modifying the structure of the chemical state.

Answer:

Entropy generation==0.12 KW/K

Explanation:

[tex]s_2-s_1=C_p\ln \frac{T_2}{T_1}-R\ln \frac{P_2}{P_1}[/tex]

[tex]s_2-s_1=0.891\ln \frac{291}{293}-0.2598\ln \frac{200}{240}[/tex]

[tex]s_2-s_1=0.0412\frac{KJ}{kg-K}[/tex]

Mass flow rate= [tex]\rho\times\dfrac{\pi}{4}d^2V[/tex]

[tex]\rho_1=\dfrac {P_1}{RT_1}[/tex]

[tex]\rho_1=\dfrac {240}{0.2598\times 293}[/tex]

[tex]\rho_1=3.51\frac{kg}{m^3}[/tex]

mass flow rate=[tex]\rho_1A_1V_1[/tex]

So by putting the values

Mass flow rate=2.97 kg/s

So entropy generation=(2.97)(0.0412)

                                    =0.12 KW/K

Answer:

(d) all of the above

Explanation:

before cutting the screw threads the operator should lubricate all of the machine parts given in the option that is lead screw and gearbox , the ways and the cross slide and the carriage and half-nuts. we should use lubrication because it reduces the overall system friction and if friction is reduced then heat generated due to friction is also decreases which is beneficial

so option (D) will be correct because we need lubricate in all the given parts  

Answer:

1. Mass = 2070 kg

2.Total length of strip = 2556 m

3. Total length of dislocation = 7.67 X[tex]10^{14}[/tex] m

Explanation:

Given:

Aluminium coil thickness, t = 0.3 mm

                                              = 0.3 X [tex]10^{-3}[/tex] m

Width of the coil,w = 1 m

Drum diameter, d = 15 cm

                              = 0.15 m

Coil outer diameter, d = 1 m

Dislocation density = [tex]10^{15}[/tex] [tex]m^{2}[/tex]

1). Area of the coil, A = [tex]\frac{\pi }{4}\times[/tex] ( [tex]d_{coil} ^{2}[/tex]-[tex]d_{drum} ^{2}[/tex])

                           A = [tex]\frac{\pi }{4}\times (1^{2}-0.15^{2})[/tex]

                           A = 0.767 [tex]m^{2}[/tex]

Volume of the coil,V = A X w

                                  = 0.767 X 1

                                  = 0.767 [tex]m^{3}[/tex]

We know density of aluminum at STP = 2.7 X [tex]10^{3}[/tex]

Therefore, mass of the aluminum coil is,

Mass,m = Density of aluminium X Volume

             = 2.7 X [tex]10^{3}[/tex] X 0.767

             = 2070 kg

Mass = 2070 kg

2). Total length of trip of coil is given by

          L = Volume of coil / area of strip

             = [tex]\frac{0.767}{1\times 0.3\times 10^{-3}}[/tex]

              = 2556 m

Total length of strip = 2556 m

3). Total length of dislocation of the coiled strip = volume X dislocation density

                                                                             = 0.767 X [tex]10^{15}[/tex]

                                                                              = 7.67 X [tex]10^{14}[/tex]

Total length of dislocation = 7.67 X[tex]10^{14}[/tex] m

Answer:

The statement is False.

Explanation:

Critical temperature is defined as the temperature at and above which the liquid and the gaseous states are indistinguishable. This is the temperature at and above which the liquid cannot be liquefied.

Above critical temperature or pressure, the substance is in supercritical fluid (SCF) state. A supercritical fluid is the one in which liquid and gaseous state can not be distinguished. It can dissolve like liquids and can effuse like solids.

Water above its critical temperature exists in SCF state which is neither vapor nor liquid.

Thus, the statement is false.

Answer:

I'm pretty sure its true

Explanation:

Low hardness is not a characteristic property of ceramic material.

Answer: Option D

Explanation:

One of the most important properties of ceramic material is the hardness that the material displays. The hardness owes to the joining of brittle fracture and plastic flow that makes the material to defend against penetration.

The hardness can be tested with the Vickers test. The hardness of ceramic makes its dominance in the use of construction purpose and manufacture of products. Other general properties are less conductivity, high melting temperature, etc.

Not a characteristic property of ceramic material (d) low hardness.

(a) High temperature stability is a defining feature of ceramics, as they can withstand extreme temperatures without significant degradation.

(b) High mechanical strength is another key characteristic, making ceramics suitable for applications where strength and durability are essential.

(c) Low elongation refers to the minimal deformation under stress, which is typical of ceramics due to their brittle nature.

(d) However, low hardness is not a characteristic property of ceramics. Ceramics are known for their high hardness, making them resistant to wear and abrasion.

Answer:

The point where all three phases coexist on a P-T diagram is called triple point.

Explanation:

A phase diagram of a substance is a graphical representation of the transition of its physical state under various temperature and pressure conditions.

A typical phase diagram usually consists of:

(A) Fusion curve - The curve that shows that the solid and the liquid state in in equilibrium with each other.

(B) Vaporization curve - The curve that shows that the liquid and the gaseous state in in equilibrium with each other.

(C) Sublimation curve - The curve that shows that the solid and the gaseous state in in equilibrium with each other.

(D) Triple point - This is a point in the phase diagram in which all the three state exists in equilibrium.

For example, Considering the phase diagram of water, The triple point occurs at a pressure of 0.6 kPa and 0.01⁰C.

The phase diagram is shown in image below:

Answer:

True

Explanation:

Moment thickness, is an index that is proportional to an increment in momentum flow due to the presence of the boundary layer.

Answer: Convective heat transfer is defined as the transfer of heat from a particular place to another with the help of fluid movements.

Explanation: Convective heat also knows as convection that is transfer of heat from one place to another place by the help of fluid movements around the area having different temperatures. This process has many examples in everyday life to understand the process better.

Ex.- the melting of ice from solid to liquid form as it comes in contact of high temperature as heat surrounds the ice in form of air.

Answer:

The correct answer is C) Trimetric

Explanation:

The most suitable answer is a trimetric projection because, in this type of projection, we see that the projection of the three angles between the axes are not equal. Therefore, to generate a trimetric projection of an object, it is necessary to have three separate scales.

Answer:

f)Density of the solid body

Explanation:

We know that heat transfer due to convection is given by

            Q=hAΔT

Where

A is the area ,which represent the geometry of solid body or surface.

h is the heat transfer coefficient which depends on

                             1.Thermal conductivity of fluid

                             2.Motion of fluid

                             3.Type of fluid flow(Laminar or Turbulent)

                             4.Viscosity of fluid

                             5.Surface condition

So from the above parameters ,we can say that heat transfer due to convection does not depends on density of the solid body.

Answer:

The temperature of the high-temperature source must increase in 12.23ºC.

Explanation:

For a Carnot engine, the efficiency is defined as:

[tex]n = 1- T2/T1 [/tex]

Where T2 and T1 are the low and the high-temperature sources respectively. Therefore for the value of T2 of 19.1ºC and the n equal to 30.7% (0.307), the T1 Temperature can be calculated as:

[tex]n = T1/T1 - T2/T1[/tex]

[tex]n = (T1-T2)/T1[/tex]

[tex]T1.n = (T1-T2)[/tex]

[tex] T1-T1.n =T2[\tex]

[tex] T1(1-n) =T2[/tex]

[tex] T1 =T2/(1-n)[/tex]

[tex] T1 = 19.1\ºC /(1-0.307)[/tex]

[tex] T1 = 27.56\ºC[/tex]

Then for the new effciencie n' of 52% (0.52) the new temeperature T1' will be:

[tex] T1' =T2/(1-n')[/tex]

[tex] T1' = 19.1\ºC /(1-0.52[/tex]

[tex] T1' = 39.79\º C[/tex]

Finally the increment of temperature is:

[tex] AT1 =T1'-T1[/tex]

[tex] AT1 =39.79\º C-27.56\º C[/tex]

[tex] AT1 =12.23\º C[/tex]

[tex] AT1 =12.23\º C[/tex]

It's an n-type dopants, as it makes the silicone n-type after the doping. so, False

Answer:

work is 50 kj

Explanation:

Given  data

heat (Q) = 50 kj

To find out

work input for the compression stroke per kilogram of air

Solution

we will apply here "first law of thermodynamics" i.e.

The First Law of Thermodynamics states that heat is a form of energy, subject to the principle of conservation of energy, that heat energy cannot be created or destroyed. It can be transferred from one location to another  location. i.e.

ΔU = Q – W                        ................1

here ΔU is change in internal energy, Q is heat and W is work done

here U = 0 because air compressor the compression takes place at a constant internal energy in question

so that by equation 1

Q = W

and Q = 50

so work will be 50 kj

Answer:

(b)False

Explanation:

We know that specific  Internal energy of gas u=[tex]C_v[/tex]T

      and specific enthalpy of gas h=[tex]C_p[/tex]T

If we take the case of air we know that

[tex]C_v[/tex]=0.707 KJ/Kg=K  , [tex]C_p[/tex]=1.005 KJ/Kg=K

If we take A fixed temperature T=300 K

so    u=212.1 KJ/ kg   ,h=301.5 KJ/kg

So we can say that specific enthaply of gas is always greater than its specific   internal energy.