If a host system is 80% efficient, the minimum horsepower rating of the motor should be ? if the hoist is to provide 20,000 ft-lb/s. a) 45.45hp b) 23,530hp c) 36.36hp d) 42.78hp

Flow energy is the energy possessed by a fluid due to its motion, which is quantified by kinetic energy density. Based on Bernoulli's equation, fluids at rest do not have flow energy but can have potential energy. The total mechanical energy of a fluid includes potential and kinetic energy components.

Flow energy refers to the energy that fluid possesses due to its motion. This form of energy can be described by kinetic energy density, which is part of the total mechanical energy in a flowing fluid. According to Bernoulli's equation, the total mechanical energy of a fluid is composed of potential energy and kinetic energy. The kinetic energy of the fluid relates to its velocity and is expressed as (1/2)ρV^2, where ρ is the density of the fluid and V is the fluid velocity. On the other hand, fluids at rest do not possess flow energy or kinetic energy related to movement, but they can still have potential energy due to their position.

According to conservation of energy principles, the work done by the fluid's pressure changes the fluid's kinetic and potential energies, per unit volume. No additional flow energy is present in a fluid at rest; however, it may still exert pressure at the bottom of a container or well due to its potential energy.

Answer:

a). Air separation plant

Explanation:

The purifier is a device that removes the pollutants or air contaminants from air to improve the air quality in a given space.

          There are basically two techniques or ways by which the air purifier makes the air contaminants free. This two techniques are active and passive.

Active air purifiers : negatively charged ions are released to the atmosphere which sticks the pollutants to the surface.

Passive air purifiers : They use air filters to eliminate pollutants and are more efficient than an active air purifiers.

Answer:

(A) Air separation plant

Explanation:

Purifier is used in air separation plant to purify the air main work of purifier is to remove the pollutants particles from the air and make the air fresh.

On the other hand it has no use team power pant because in steam power plant we don't need to purify the steam and also not used in fuel cell and refrigerator

So purifiers are used in the air separation plant.

Solution:

Given:

[tex]T_{H}[/tex] = 1200 K

[tex]T_{L}[/tex] = 600 K

Q = 100 kJ

The Entropy change of the two reservoirs is given by the sum of entropy change of each reservoir system and is given by the formula:

[tex]\Delta s = \frac{-Q}{T_{H}}+\frac{Q}{T_{L}}[/tex]

[tex]\Delta s = \frac{Q(T_{L}-T_{_{H}})}{T_{H}T_{L}}[/tex]

[tex]\Delta s = \frac{-100(600-1200)}{1200\times 600}[/tex]

[tex]\Delta s = 0.0833kJ/K

Since, the change in entropy is positive and according to the Increase in entropy principle, for any process the total change in entropy of a system is always greater than or equal to zero (with its enclosing adiabatic surrounding).

Therefore, the entropy principle is satisfied.

Answer:

(d) a and c are correct

Explanation:

METALS : Metal are those materials which has very high ductility, high modulus of elasticity, good thermal and electrical conductivity

for example : iron, gold ,silver, copper

ALLOYS: Alloys are those materials which are made up of combining of two or more than two metals these also have good thermal and electrical conductivity and me liable property

for example ; bronze and brass

so from above discussion it is clear that option (d) will be the correct option

Answer:

d)-a and c are correct

Explanation:

Hello,

As long as metals have specific molecular arrangements (closely assembled molecules) they have a high capacity to transfer both electrical and thermal energy. On the other hand, the modulus of stability is considered as a measure of material's stiffness or resistance to elastic deformation, thus, due to the very same aforesaid molecular arrangement of metals, they are hard to deform so that modulus is considered as high.

Best regards.

Answer:

Enthalpy at outlet=284.44 KJ

Explanation:

[tex]m_1=1 Kg/s,m_2=1.5 Kg/s,m_3=22 Kg/s[/tex]

[tex]h_1=100 KJ/Kg,h_2=120 KJ/Kg,h_3=500 KJ/Kg[/tex]

We need to Find enthalpy of outlet.

Lets take the outlet mass m and outlet enthalpy h.

So from mass conservation

[tex]m_1+m_2+m_3=m[/tex]

   m=1+1.5+2 Kg/s

  m=4.5 Kg/s

Now from energy conservation

[tex]m_1h_1+m_2h_2+m_3h_3=mh[/tex]

By putting the values

[tex]1\times 100+1.5\times 120+2\times 500=4.5\times h[/tex]

So h=284.44 KJ

Answer:

(b)     Irreversible cycle.

Explanation:

 Given;

 [tex]T_2=540R ,Q_2= 500 Btu/s ,T_1=240 R ,Q_1= 200 Btu/s [/tex]

To find the validity of cycle

      [tex]\oint _R\frac{dQ}{T}\leq0[/tex]

If it is zero then cycle will be reversible cycle and if it is less than zero then cycle will be irreversible cycle.These are possible cycle.

If it is greater than zero ,then cycle will be impossible .

Now find

[tex]\dfrac{Q_1}{T_1}-\dfrac{Q_2}{T_2}=\dfrac{200}{240}-\dfrac{500}{540}[/tex]

[tex]\dfrac{Q_1}{T_1}-\dfrac{Q_2}{T_2}[/tex]= -0.09

It means that this  cycle is a irreversible cycle.

Answer:

the answer is true when designing sold rockets thrust and mass flow

Answer:

Reliability of system = 99.9992%

Explanation:

Given Reliability of item = 98%

therefore probability of failure = 100%-98% =2%

For system in parallel the probability of failure is product of individual probabilities of items

thus

[tex]Probabilityfail_{system}=p_{1}\times p_{2}\times p_{3}\\\\Probabilityfail_{system}=0.02^{3}=0.000008\\\\Realibility_{system}=100- Probabilityfail_{system}\\\\Realibility_{system}=99.9992%[/tex]

Answer: Mollier diagram is the diagram or graph representing the relation established between enthalpy ,air, moisture and temperature.  

Explanation: Mollier graph represents the basic thermodynamic properties along with terms of enthalpy and entropy. The factors like air, moisture , temperature etc. are plotted on the graph which makes it easy to understand. It is used in the field building designers and engineer.They are usually plotted for the gases with purity with general pressure and temperature.

Answer:

The correct answer is C. World Coordinate System

Explanation:

The World Coordinate System has to do with that coordinate system which is fixed in the activities of the CADing. There is a default system in which we can refer to them as soon as we want to manipulate the objects and add new elements.

Answer:

Weight of the can is 5 N

Explanation:

The weight of the can is a downward force. When an object floats in a fluid, it is acted upon by an upward force which balances the weight of the body that acts downwards. This upward force is know as Buoyant force. This buoyant force is also the weight of the fluid displaced by the object.

          Therefore, we know that

Total buoyant force = total weight of the body  

And total weight of the body is nothing but the weight of the fluid displaced by the body.

So, weight of the body = weight of the fluid displaced by the body.

                                      = [tex]\rho g\times[/tex]volume of water displaced by the body.

                                     = [tex]\rho g\times[/tex]volume of the body submerged in the water

Now we know that,

density of water, [tex]\rho[/tex] = 1000 kg/[tex]m^{3}[/tex]

acceleration due to gravity, g = 9.81 m/[tex]s^{2}[/tex]

Volume of the body submerged in water, V = [tex]\frac{\prod }{4}\times d^{2}\times h[/tex]

       = [tex]\frac{\prod }{4}\times 0.09^{2}\times 0.08[/tex]

       = 5.05[tex]\times 10^{-4}[/tex] [tex]m^{3}[/tex]

Therefore, weight of can = [tex]\rho g\times[/tex]volume of the body submerged in the water

                                        = 1000[tex]\times 9.81\times 5.05\times 10^{-4}[/tex]

                                        = 4.95 N

                                        [tex]\simeq[/tex] 5 N

Therefore the weight of the can is 5 N.

Answer:

The correct option is C) Cobalt

Explanation:

The cemented carbides are hard substances which are extensively used as cutting tools materials. In the cemented carbides, substances like tungsten-carbide are used as aggregates.

A tungsten carbide- cobalt cutting tool is a metal matrix composite, in which the tungsten carbide is the aggregate and the cobalt is the matrix.

Therefore, in the tungsten carbide cutting tool, cobalt is used as the matrix.

Given:

mass of water, m = 2000 kg

temperature, T = [tex]30^{\circ}C[/tex] = 303 K

extacted mass of water = 100 kg

Atmospheric pressure, P = 101.325 kPa

Solution:

a) Using Ideal gas equation:

PV = m[tex]\bar{R}[/tex]T                                        (1)

where,

V = volume

m = mass of water

P = atmospheric pressure

[tex]\bar{R} = \frac{R}{M} [/tex]

R= Rydberg's constant = 8.314 KJ/K

M = molar mass of water = 18 g/ mol

Now, using eqn (1):

[tex]V = \frac{m\bar{R}T}{P}[/tex]

[tex]V = \frac{2000\times \frac{8.314}{18}\times 303}{101.325}[/tex]

[tex]V = 2762.44 m^{3}[/tex]

Therefore, the volume of the tank is [tex]V = 2762.44 m^{3}[/tex]

b) After extracting 100 kg of water, amount of water left, m' = m - 100

m' = 2000 - 100 = 1900 kg

The remaining water reaches thermal equilibrium with surrounding temperature at T' = [tex]30^{\circ}C[/tex] = 303 K

At equilibrium, volume remain same

So,

P'V = m'[tex]\bar{R}[/tex]T'

[tex]P' = \frac{1900\times \frac{8.314}{18}\times 303}{2762.44}[/tex]      

Therefore, the final pressure is P' = 96.258 kPa

Answer:

The typical bonding in conductors is defined as which contain free valence electrons and free ions as, it is typically known as metallic bonding. In a group of free electrons metallic ions are made up from lattice and to conduct the electricity the free electron are the main reason for ability of the metals.

On the other hand, semiconductors can be arranged as structure of lattice and also there is a covalent bonds are present.

Answer:

True

Explanation:

By definition of steady flow we have

[tex]\frac{\partial f(x,y,z,t) }{\partial t}=0[/tex]

where f(x,y,z,t) is any property of the system under consideration

=> f(x,y,z,t) = constant

Answer:

The temperature at which observed heat is 400 K

Explanation:

Given data:

rejection reservoir temperature at exit [tex]T_{L}[/tex] is 300 k

the efficiency of a engine is  η = 25%

we know that efficiency of Carnot is given as

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

Putting all value to obtained  temperature at which observed heat

[tex]0.25 = (1-\frac{300}{T_{H}})[/tex]

[tex]T_{H}[/tex] = 400 K

Answer:

option (a)

Explanation:

t = 5 sec, α = 2 rad/s^2, f0 = 20 rpm = 20 / 60 rps

Use second equation of motion for rotational motion

θ = ω0 x t + 1/2 α t^2

θ = 2 x 3.14 x 5 x 20 / 60 + 0.5 x 2 x 5 x 5

θ = 10.47 + 25 = 35.47 rad

Number of revolution = 35.47 / (2 x 3.14) = 5.65

Answer:

Transfer function for feedback path is given by:

[tex]\frac{C(s)}{R(s)}[/tex]=[tex]\frac{G(s)}{1+G(s)H(s)}[/tex]       (1)

Explanation:

with reference to fig1:

two blocks in series are multiplied:

[tex]\frac{5}{s(s+1)}[/tex]

for feedback function:

1+G(s)H(s)=[tex]1+\frac{5}{s+1}.\frac{2}{s}[/tex]

Now from eqn (1):

[tex]\frac{C(s)}{R(s)} = \frac{5}{s(s+1)+10}[/tex]

Answer:

False

Explanation:

Just-in-time manufacturing means that production is done when there is demand. It is a pull system which means that demand dictates production. Lean manufacturing is method of production which aims to reduce the seven types of waste which are

Logistics

Inventory

Motion of objects during manufacturing

Unnecessary delay

Producing more than demand

Over Processing of goods

Malfunctioning items.

Here it can be seen that Producing more than demand is a waste. This can be reduced by Just in Time manufacturing.

Answer:

23.3808 kW

20.7088 kW

Explanation:

ρ = Density of oil = 800 kg/m³

P₁ = Initial Pressure = 0.6 bar

P₂ = Final Pressure = 1.4 bar

Q = Volumetric flow rate = 0.2 m³/s

A₁ = Area of inlet = 0.06 m²

A₂ = Area of outlet = 0.03 m²

Velocity through inlet = V₁ = Q/A₁ = 0.2/0.06 = 3.33 m/s

Velocity through outlet = V₂ = Q/A₂ = 0.2/0.03 = 6.67 m/s

Height between inlet and outlet = z₂ - z₁ = 3m

Temperature to remains constant and neglecting any heat transfer we use Bernoulli's equation

[tex]\frac {P_1}{\rho g}+\frac{V_1^2}{2g}+z_1+h=\frac {P_2}{\rho g}+\frac{V_2^2}{2g}+z_2\\\Rightarrow h=\frac{P_2-P_1}{\rho g}+\frac{V_2^2-V_1^2}{2g}+z_2-z_1\\\Rightarrow h=\frac{(1.4-0.6)\times 10^5}{800\times 9.81}+\frac{6.67_2^2-3.33^2}{2\times 9.81}+3\\\Rightarrow h=14.896\ m[/tex]

Work done by pump

[tex]W_{p}=\rho gQh\\\Rightarrow W_{p}=800\times 9.81\times 0.2\times 14.896\\\Rightarrow W_{p}=23380.8\ W[/tex]

∴ Power input to the pump 23.3808 kW

Now neglecting kinetic energy

[tex]h=\frac{P_2-P_1}{\rho g}+z_2-z_1\\\Righarrow h=\frac{(1.4-0.6)\times 10^5}{800\times 9.81}+3\\\Righarrow h=13.19\ m\\[/tex]

Work done by pump

[tex]W_{p}=\rho gQh\\\Rightarrow W_{p}=800\times 9.81\times 0.2\times 13.193\\\Rightarrow W_{p}=20708.8\ W[/tex]

∴ Power input to the pump 20.7088 kW

Answer and Explanation:

TEMPERATURE DEPENDENCY ON ELECTRICAL CONDUCTIVITY OF METALS : Metals are good conductors of electricity but when we increase the temperature the free electrons of metals collide with each other due to heat.There collision become very fast and so the resistance increases and so the electrical conductivity of metals decreases on increasing temperature.    

TEMPERATURE DEPENDENCY ON ELECTRICAL CONDUCTIVITY OF SEMICONDUCTOR : The electrical conductivity of semiconductor is mainly sue to presence of impurities and defects as the temperature increases the impurities and defects also increases so the electrical conductivity of semiconductor increases on increasing temperature.

Answer:

False

Explanation:

A graphical representation of transition of substance's physical state under various temperature and pressure conditions is known as phase diagram.

A typical phase diagram usually consists of:

(A) Fusion curve - The curve that represents that the solid and the liquid state exists in the equilibrium with each other is called fusion curve.

(B) Vaporization curve - The curve that represents that the liquid and the gaseous state exists in the equilibrium with each other is called fusion curve.

(C) Sublimation curve - The curve that represents that the solid and the gaseous state exists in the equilibrium with each other is called fusion curve.

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

Thus, for a pure substance, sublimation line exist as a mixture of solid and gas. The statement is false.

Answer:

Listed Below

Explanation:

Weldability which is also known as joinability is defined as the ease with which  a material can be welded without producing any other effect .

Some factors which affect weldability are

1.Melting point of metal

2.Thermal conductivity

3.Reactivity

4.Coefficient of thermal expansion(α)

5.Surface condition

Answer:

The correct answer to the given statement is

option D. All of the above

Explanation:

Analysis of proper grain stress/strain is important as it ensures good mechanical motor structure.

With the help of analysis surface cracks can be checked and proper maintenance can be provided. It further helps in keeping check in order to avoid separation of bonds.

Therefore, qualitative analysis and in depth analysis can reduce errors and helps to maintain the qualitative parameters.

Answer: c)-Yes, spheroidized steel are considered as composite.the dispersed phase is  iron carbide.

Explanation: Spheroidized steel are the alloy that have iron as the basic part that have been heat treated to increase their ductility and malleability property .They are considered as composite because they are made up of  iron alloys.  The heat treatment is usually for the carbon steel and so the dispersed phase that is obtained is iron carbide.

Answer:

(e) 2487 W

Explanation:

Given data

voltage = 120 V

power = 2.5 hp

efficiency = 75%

To find out

watts draw from the power line

solution

we calculate efficiency by given formula

efficiency = ( output / input ) × 100     ............1

we know our output is 2.5 hp = 2.5 ×  746 = 1865 W

and efficiency is 75% = 0.75

put these value in equation 1 and find out input power

power = ( 1865 / 0.75 )

power =  2486.66 W

so our answer is (e) 2487 W

Answer: Static Balancing is when a stationary object has the the ability to balance because its core centre of gravity is on the axis of rotation.

Given:

diameter of sphere, d = 6 inches

radius of sphere, r = [tex]\frac{d}{2}[/tex] = 3 inches

density,  [tex]\rho}[/tex] = 493 lbm/ [tex]ft^{3}[/tex]

S.G = 1.0027

g = 9.8 m/ [tex]m^{2}[/tex] = 386.22 inch/ [tex]s^{2}[/tex]

Solution:

Using the formula for terminal velocity,

[tex]v_{T}[/tex] = [tex]\sqrt{\frac{2V\rho  g}{A \rho C_{d}}}[/tex]              (1)

[tex](Since, m = V\times \rho)[/tex]

where,

V = volume of sphere

[tex]C_{d}[/tex] = drag coefficient

Now,

Surface area of sphere, A = [tex]4\pi r^{2}[/tex]

Volume of sphere, V = [tex]\frac{4}{3} \pi r^{3}[/tex]

Using the above formulae in eqn (1):

[tex]v_{T}[/tex] = [tex]\sqrt{\frac{2\times \frac{4}{3} \pir^{3}\rho  g}{4\pi r^{2} \rho C_{d}}}[/tex]

[tex]v_{T}[/tex] = [tex]\sqrt{\frac{2gr}{3C_{d}}}[/tex]  

[tex]v_{T}[/tex] = [tex]\sqrt{\frac{2\times 386.22\times 3}{3C_{d}}}[/tex]

Therefore, terminal velcity is given by:

[tex]v_{T}[/tex] = [tex]\frac{27.79}{\sqrt{C_d}}[/tex] inch/sec

The two windings of transformer is c)- Inductively linked

Hope this helped!

Answer:

The two windings of transformer is Inductively linked -c)