Critical Reynolds number for internal turbulent flow is 500,000. a) True b) False

Answer:

[tex]\frac {p_2- p_1}{\rho g} = 31.06 m[/tex]

Explanation:

from bernoulli's theorem we have

[tex]\frac{p_1}{\rho g} + \frac{v_1^{2}}{2g} +z_1 = \frac{p_2}{\rho g} + \frac{v_2^{2}}{2g} +z_2  + h_f[/tex]

we need to find pressure head difference i.e.

[tex]\frac {p_2- p_1}{\rho g} = (z_1 - z_2) - h_f[/tex]

where h_f id head loss

[tex]h_f = \frac{flv^{2}}{D 2g}[/tex]

velocity v =[tex] \frac{1}{n} * R^{2/3} S^{2/3}[/tex]

[tex]S = \frac{\delta h}{L} = \frac{40}{150} = 0.267[/tex]

hydraulic mean radius R =[tex] \frac{A}{P} = \frac{hw}{2h+w} [/tex]

[tex]R = \frac{40*1}{2*40+1} = 0.493 m[/tex]

so velocity is  =[tex] \frac{1}{0.013} * 0.493^{2/3} 0.267^{1/2}[/tex]

v = 24.80 m/s

head loss

[tex]h_f = \frac{0.0019*150*24.80^{2}}{1* 2*9.81}[/tex]

[tex]h_f  =8.93 m[/tex]

pressure difference is

[tex]\frac {p_2- p_1}{\rho g} = 40 - 8.93 = 31.06 m[/tex]

[tex]\frac {p_2- p_1}{\rho g} = 31.06 m[/tex]

Answer:

Harmful effect associated with extraction of Aluminum, Gold and Copper are:

During the melting of aluminium there is a released of per fluorocarbon are more harmful than carbon dioxide in the environment as they increased the level of green house gases and cause global warming. The process of transforming raw material into the aluminium are much energy intensive.

Gold mining industries destroyed land scopes and increased the amount of toxic level in the environment and they also dump there toxic waste in the natural water bodies, which increased the level of water pollution in the environment.

Copper mining causes the health problems like asthma and problem in respiratory system because of the inhalation of silica dust. It also increased the level of sulfur diode in the environment which cause acid rain and destroyed various trees and buildings in the nature.

Answer:227.56 mm

Explanation:

Given data

Elastic modulus[tex]\left ( E\right )[/tex]= 117 GPa

Diameter[tex]\left ( d\right )[/tex]=3.6mm

force applied[tex]\left ( F\right )[/tex]=2460N

Area of cross-section[tex]\left ( A\right )[/tex]=[tex]\frac{\pi}{4}\times d^{2}[/tex]=10.18[tex]mm^{2}[/tex]

and change in length is given by

[tex]\Delta L[/tex]=[tex]\frac{FL}{AE}[/tex]

[tex]\Delta {0.47\times 10^{-3}}[/tex]=[tex]\frac{2460\times L}{10.180\times 117\times 10^{3}}[/tex]

L=[tex]0.47\times 10^{-3}\times 10.18\times 117\times 10^{3][/tex]

L=227.56 mm

Given:

[tex]\sigma _{s} = 2.8\times 10^{4} \Omega-m[/tex]

electron concentration, n = [tex]2.9\times 10^{22} m^{-3}[/tex]

[tex]\mu _{h} = 0.14[/tex]

[tex]\mu _{e} = 0.023[/tex]

Solution:

Let holes concentration be 'p'

[tex]\sigma _{s}[/tex] = ne[tex]\mu _{e}[/tex] +pe[tex]\mu _{h}[/tex]     (1)

substituting all given values in eqn (1):

[tex]2.8\times 10^{4} = 2.9\times 10^{22}\times 1.6 \times 10^{-19}\times 0.14 + p\times1.6 \times 10^{-19}\times 0.023[/tex]

The cocentration of holes is:

[tex]p = 7.432\times 10^{24} m^{-3}[/tex]

Answer:

The correct option is : d) b and c.

Explanation:

A superalloy, also known as a high performance alloy, is a class of alloys that shows the following characteristics: high mechanical strength, surface stability, resistance to thermal creep and resistance to oxidation or corrosion at high temperatures.

Therefore, a nickel base superalloy is commonly used for the high temperature gas turbine blades because of high thermal creep strength and high maximum working temperature due to its stability at high temperatures.

Answer:

The correct option is  (e) η = 0.66

Explanation:

given data:

temperature at entry is 627 degree C

temperature at exit is 27 degree C

the efficiency of a engine is given as η

[tex]\eta = (1-\frac{T_{L}}{T_{H}})*100[/tex]

where [tex]T_{L}[/tex] is temperature in kelvin at exit point

          [tex]T_{H}[/tex] is temperature in kelvin at entry point

[tex]\eta = (1-\frac{27+273}{627+273})*100[/tex]

η = 66.66 %

Answer:

Volumetric flow rate = 0.4773 m³/s

Mass flow rate = 477.3 kg/s

It will take 286.38 seconds to fill a tank with measurements 5 m x 6 m x 20 m

Explanation:

Given:

Diameter of the pipe through which the water is flowing = 450 mm

Radius = Diameter/2

Thus, Radius of the pipe = 225 mm

The conversion of mm into m is shown below:

1 mm = 10⁻³ m

Radius of the pipe = 225×10⁻³ m

The area of the cross-section = π×r²

So, Area of the pipe = π×/(225×10⁻³)² m² = 0.1591 m²

Also, Given : The water flowing rate = 3 m/s

Volumetric flow rate is defined as the amount of flow of the fluid in 1 sec.

[tex]Volumetric\ flow= \frac {Volume\ passed}{Time taken}[/tex]

This, can be written as Velocity of the fluid from the cross-section area of the pipe.

Q = A×v

Where,

Q is Volumetric flow rate

A is are though which the fluid is flowing

v is the velocity of the fluid

So,

Q = 0.1591 m²×3 m/s = 0.4773 m³/s

Mass flow rate is defined as the mass of the fluid passes per unit time.

[tex]\dot {m}= \frac {Mass\ passed}{Time taken}[/tex]

The formula in terms of density can be written as:

[tex]Density=\frac{Mass}{Volume}[/tex]  

So, Mass:

[tex]Mass= Density \times {Volume}[/tex]

Dividing both side by time, we get:

[tex]\dot {m}= Density \times {Q}[/tex]

Where,

[tex]\dot {m}[/tex] is the mass flow rate

Q is Volumetric flow rate

Density of water = 1000 kg/m³

Thus, Mass flow rate:

[tex]\dot {m}= 1000 \times {0.4773} Kgs^{-1}[/tex]

Mass flow rate = 477.3 kg/s

The time taken to fill the volume of measurement 5 m× 6 m× 20 m can be calculated from the formula of volumetric flow rate as:

t= Q×V

So,

Volume of Cuboid = 600 m³

Time = 0.4773 m³/s × 600 m³ = 286.38 s

Answer:

d = 13 mm

d =  15.68 mm

Explanation:

Given data

force = 20000 N

stress = 150 N/mm²

strain = 0.0005

E = 207 GPa

Solution

we know stress = force / area

so 0.0005 = 20000 / area

area = [tex]\pi[/tex]/4 × d²

put the area in stress equation and find out d

d² = 4×force / [tex]\pi[/tex] ×stress

d² = 4× 20000 / [tex]\pi[/tex] ×150

d = [tex]\sqrt{ 4× 20000 / [tex]\pi[/tex] ×150}[/tex]

d = 13 mm

and now we know starin = stress / E

same like stress we find d here

d = [tex]\sqrt{ 4× 20000 / [tex]\pi[/tex] ×0.0005×207×10³ }[/tex]

so d =  15.68 mm

Answer:

a). d = 13 mm

b). d = 16 mm

Explanation:

a). Given :

  Force = 20000 N

  Maximum stress, σ = 150 N/[tex]mm^{2}[/tex]

Therefore, we know that that

σ = [tex]\frac{Force}{area}[/tex]

150 = \frac{Force}{\frac{pi}{4}\times d^{2}}

150 = \frac{20000}{\frac{pi}{4}\times d^{2}}

[tex]d^{2}[/tex] = 169.76

d = 13.02 mm

d [tex]\simeq[/tex] 13 mm

b). Given :

   Strain, ε =  0.0005

   Young Modulus, E =  207 GPa

                                   = 207[tex]\times[/tex][tex]10^{3}[/tex] MPa

Therefore we know that, Stress σ = E[tex]\times[/tex]ε

                                                         = 207[tex]\times[/tex][tex]10^{3}[/tex][tex]\times[/tex]0.0005

                                                         = 103.5 N/[tex]mm^{2}[/tex]

We know that  

σ = [tex]\frac{Force}{Area}[/tex]

103.5 = [tex]\frac{Force}{\frac{pi}{4}\times d^{2}}[/tex]

[tex]d^{2}[/tex] = 246.27

d = 15.69 mm

d [tex]\simeq[/tex]16 mm

Answer:

(d)

Explanation:

Absolute pressure= Atmospheric pressure+Gauge pressure

hence from this equation we can clearly say that option (A) and (b) is not right.

absolute temperature cannot be negative.

so, option (d) is right.

according to law of mass conservation mass can neither be created nor be destroyed which define control mass i.e. mass in a control mass system is constant

Absolute pressure is calculated by adding the gauge pressure to the atmospheric pressure, represented as Pabs = Pg + Patm. This principle is fundamental in physics, especially for calculations involving fluid dynamics and pressure measurements.

The correct relationship between absolute pressure, gauge pressure, and atmospheric pressure is crucial in understanding various phenomena in physics related to fluid dynamics and pressure measurements. Absolute pressure is the total pressure exerted on a system, which includes the atmospheric pressure plus the gauge pressure. Gauge pressure, on the other hand, is the pressure of a system over and above the atmospheric pressure. It is a practical measurement used in most applications because it measures pressure relative to the atmosphere's pressure. In formulas, this relationship is represented as Pabs = Pg + Patm, where Pabs is absolute pressure, Pg is gauge pressure, and Patm is atmospheric pressure.

For example, if a tyre gauge reads 34 psi, this measurement is the gauge pressure. To find the absolute pressure, one must add the atmospheric pressure to this gauge pressure. Considering the atmospheric pressure to be 14.7 psi, the absolute pressure would then be 48.7 psi (which is 34 psi + 14.7 psi). This calculation is fundamental in physics for accurate pressure-related measurements and analyses, especially in applications employing the ideal gas law and other pressure-dependent principles.

Answer:

The given statement is true.

Explanation:

Answer:

true.

Explanation:

but i am not 100% sure

Answer:

[tex]\eta =\dfrac{(h_3-h_4)-(h_2-h_1)}{(h_3-h_5)}[/tex]

Explanation:

generally regeneration of cycle is used in the case of gas turbine. due to regeneration efficiency of turbine is increased but there is no effect on the on the net work out put of turbine.Actually in regeneration net heta input is decreases that is why total efficiency  increase.

 Now from T-S diagram

    [tex]W_{net}=W_{out}-W_{in}[/tex]

   [tex]W_{net}=(h_3-h_4)-(h_2-h_1)[/tex]

  [tex]Q_{in}=h_3-h_5[/tex]

  Due to generation [tex](h_5-h_2)[/tex] amount of energy has been saved.

  [tex]Q_{generation}=Q_{saved}[/tex]

So efficiency of cycle [tex]\eta =\frac{W_{net}}{Q_{in}}[/tex]

  [tex]\eta =\dfrac{(h_3-h_4)-(h_2-h_1)}{(h_3-h_5)}[/tex]

Effectiveness of re-generator

  [tex]\varepsilon =\dfrac{(h_5-h_2)}{(h_4-h_2)}[/tex]

So the efficiency of regenerative cycle

[tex]\eta =\dfrac{(h_3-h_4)-(h_2-h_1)}{(h_3-h_5)}[/tex]

The answer is : True

Answer:

Out of the given options

option (b) CH

is correct.

Explanation:

'CH' is not an oxidizer, it is a reducing agent.

Oxidizer or oxidizing agents are those substances that  undergo chemical reactions in order to accept one or more electrons from atoms of other substances and are  able to oxidize these substances. Oxidizers are electron acceptor species and are themselves reduced. Some of the examples of Oxidizers are oxygen,halogens, etc.

Answer:

a) reciprocating pump

b) rotary pump

c) linear pump

Explanation:

Positive displacement pump has enlarged  cavity on the suction side and decreasing cavity on the discharge side and in  positive displacement pump

the amount of fluid captured and inside and then discharged is same.

There are three type of positive displacement pump

a) reciprocating pump is the pump which two valve during suction outlet valve is closed and  for delivery the inlet valve is closed and pump is used for discharge

b) rotary pump fluid move with the help of rotary the rotation of rotary displaces water.

c) linear pump is the pump in which displacement is linear rope and chain pump is example of this type of pump.

Answer: True

Explanation: It is correct that during a cycle the energy of the system remains unchanged. Total energy consist of the initial energy and the final energy in a system and both remain equal in a system whether they are in cycle or not  ans also according to the law of conservation of energy ,total energy cannot be destroyed or created. Thus the while a cycle goes on energy will remain the same.

Answer:

[tex]K=C+273.15[/tex]

Explanation:

Kelvin's climbing represents the absolute temperature. Temperature is a measure of the molecular kinetic energy of translation. If the molecules move quickly, with the same energy as in the walls of the container, which makes us feel like "heat". If the molecules do not move, the temperature is zero. 0 K.

The Celsius scale has an artificial zero, defined in the solidification temperature of the water. It is very useful to talk about the weather, and about some simpler technical matters. But it is artificial.

Conduction of electricity is actually just flow of electrons which is a charge carrier. So, answer is "c) Charge carriers"

Answer:0.646 KJ

Explanation:

Using First law for cycle

[tex]\sum Q=\sum W[/tex]

[tex]\sum Q=Q_{1-2}+Q_{3-4}[/tex]

For adiabatic process heat transfer is zero and for isothermal process

d(Q)=d(W)

[tex]Q_{1-2}=mRT_1\ln {\frac{P_1}{P_2}}[/tex]

Given [tex]P_1=2000KPa[/tex]

[tex]P_3=20KPa[/tex]

[tex]\left (\frac{T_2}{T_3}\right )^{\frac{\gamma }{\gamma -1}[/tex]=[tex]\left (\frac{P_2}{P_3}\right )}[/tex]

[tex]P_2=1089.06K[/tex]

[tex]Q_{1-2}=0.0058\dot 0.287\dot 940\ln \frac{2000}{1089.06}[/tex]=[tex]0.95KJ[/tex]

[tex]Q_{3-4}=mRT_2\ln {\frac{P_3}{P_4}}[/tex]

[tex]\left (\frac{T_1}{T_4}\right )^{\frac{\gamma }{\gamma -1}[/tex]=[tex]\left (\frac{P_1}{P_4}\right )}[/tex]

Now we have to find [tex]P_4=36.72KPa[/tex]

[tex]Q_{3-4}=0.0058\dot 0.287\dot 300\ln \frac{20}{36.72}[/tex]=[tex]-0.30341KJ[/tex]

[tex]Q_{net}=Q_{1-2}+Q_{3-4}[/tex]

[tex]Q_{net}=0.95-0.303=0.646KJ[/tex]

[tex]Q_{net}=W_{net}=0.646KJ[/tex]

Answer:0.1898 Pa/m

Explanation:

Given data

Diameter of Pipe[tex]\left ( D\right )=0.15m[/tex]

Velocity of water in pipe[tex]\left ( V\right )=15cm/s[/tex]

We know viscosity of water is[tex]\left (\mu\right )=8.90\times10^{-4}pa-s[/tex]

Pressure drop is given by hagen poiseuille equation

[tex]\Delta P=\frac{128\mu \L Q}{\pi D^4}[/tex]

We have asked pressure Drop per unit length i.e.

[tex]\frac{\Delta P}{L} =\frac{128\mu \ Q}{\pi D^4}[/tex]

Substituting Values

[tex]\frac{\Delta P}{L}=\frac{128\times8.90\times10^{-4}\times\pi \times\left ( 0.15^{3}\right )}{\pi\times 4 \times\left ( 0.15^{2}\right )}[/tex]

[tex]\frac{\Delta P}{L}[/tex]=0.1898 Pa/m

Answer  and Explanation:

The two principles or corollaries of Carnot Theorem are listed below:

1). The efficiencies of all the reversible heat engines between any two thermal reservoirs working between the same temperatures will be equal to each other.

2). For every Carnot engine working between any two thermal reservoirs will have the same efficiency independent of the operating conditions and the nature of working substance. It only depends on the temperature of the thermal energy reservoirs.

Answer: Metals are good thermal conductors because they have close packaged metal ions in their lattice structure but in polymers they have discontinuous structure which make them poor as a conductor.

Explanation: Metals are considered as good thermal conductors because of their lattice structure which has tightly packed ions in it. In the outer shell of atoms the electrons are free to move and thus conduct the electricity but for the polymers, they have a different structure as compared to metals thus it makes it difficult for a polymer to conduct electricity due to high number of discontinuous particle chains. Therefore metals are good conductors , but polymers are not.

Answer:

d). a and c

Explanation:

According to Pascal's law, when force is applied to a fluid, the pressure will increase equally in all direction of the container. Pascal law says that the pressure is transmitted undiminised in all direction inside a closed container. And the pressure inside the closed container is constant when measured at the same height above the datum.

Hence option d is correct.

Answer:

125 Pascal

Explanation:

We know that

[tex]Pressure=\frac{Force}{Area}[/tex]

Applying given values we get

[tex]Pressure=\frac{250N}{2m^{2}}[/tex]

[tex]Pressure=125\frac{N}{m^{2}}[/tex]

Pressure = 125 Pascal

Answer:

Stress is a tensor quantity and tensor quantities require 2 sub scripts for their complete definition. 1 subscript defines force and the other area.

Explanation:

Stress at a point is defined as follows

[tex]\sigma =\lim_{\Delta a\rightarrow 0}\frac{\overrightarrow{\Delta F}}{\Delta A}[/tex]

In the expression above in addition to the direction of force F we also need to define orientation of the area that we choose in defining the limit of the quantity on right hand side of the expression above hence we get a dobule subscript notation in stress at a point. 1 subscript defines force and the other area.

Answer:

Explanation:

b) This statement is False

A beam is a structural member that carries load in the direction perpendicular to its longitudinal axis or we can say that a beam is subjected to transverse loads. Generally, all loads act in the vertical direction, either upward or downward, i.e., remain perpendicular to its longitudinal axis

Answer: Extensive property is a property of matter that changes as the amount of matter changes.  

Explanation: An extensive property is explained as a property changes as the amount of matter changes and it is measured without any chemical change occurring. For example mass and volume are extensive properties. As more matter is added to a system, mass and volume both changes. It basically do not depend on the size of the system, nor the amount present  in the system.  

Answer:

Critical Reynolds number is a number or the threshold or the limit at which the laminar flow changes to turbulent flow.

Explanation:

It is basically the ratio of inertial forces to viscous forces and helps to predict if the flow is laminar or turbulent.

from the experiments, for flow in a pipe of diameter D, critical Reynolds number=2300

For Laminar flow: Reynolds number is less than 2000

For transitional flow: Reynolds number is in between 2000-4000, the flow is unstable

For Turbulent flow: Reynolds number is greater than 3500

Reynolds number is different for different geometries

Answer:

Explanation:

k_max = 26.9 w/mk

  k_min  =  22.33 w/mk

Explanation:

a) the maximum thermal conductivity is given as

K_MAX = k_m v_m + k_p v_p

where k_m is thermal conductvitiy of metal

k_p is thermal conductvitiy of carbide

v_m = proportion of metal in the cement = 0.15

v_p = proportion of carbide in the cement = 0.85

[tex]K_MAX = k_m v_m + k_p v_p[/tex]

            = 66*0.15 + 20*0.85

           k_max = 26.9 w/mk

b) the minimum thermal conductivity is given as

[tex]k_min = \frac{ k_{carbide} *k_{metal}}{k_{metal} v_{carbide} +k_{carbide} v_{metal}}[/tex]

          = \frac{20*66}{20*0.15 +66*0.85}

        k_min  = 22.33 w/mk

Answer:

0.8

Explanation:

Given:

[tex]h_{oil}[/tex] = 0.35m

[tex]h_{water}[/tex] = 0.28m

Equating the pressure in the manometer at both ends

we have

Pressure at the left limb = Pressure at right limb

[tex]\rho_{oil} gh_{oil}=\rho_{water} gh_{water}[/tex]

substituting the values in the above equation, we get

[tex]\rho_{oil}\times g\times 0.35=\rho_{water}\times g\times 0.28[/tex]

[tex]\frac{\rho_{oil}}{\rho_{water}} =\frac{ 0.28}{0.35}[/tex]

[tex]\frac{\rho_{oil}}{\rho_{water}} =0.8[/tex]

we know that specific gravity is defined as the ratio of the density of the fluid with respect to the density of water

thus, SG of oil = 0.8