Nguồn điện là một yêu cầu thiết yếu của các ngành công nghiệp. Biến tần là một thiết bị độc lập có chức năng chuyển đổi điện áp một chiều thành điện áp xoay chiều. Biến tần đảm bảo rằng việc cung cấp điện không bị gián đoạn và liên tục. ... Các ngành công nghiệp yêu cầu sử dụng bộ nghịch lưu công nghiệp để hoạt động liên tục của các hoạt động trong ngành.
there are many different values associated with an AC sine wave which one of the following continually changes throughout the cycle?
A. instantaneous value
b. effective value
c. peak value
d. average value
A. The instantaneous value (of voltage for sure and also possibly of current) continually changes thought the cycle.
Sine waves are by far the most common type of alternating current waveform employed in electrical engineering. The correct option is A.
What are Sine Waves?Sine waves are by far the most common type of alternating current waveform employed in electrical engineering. An AC Waveform is the shape formed by charting the instantaneous ordinate values of either voltage or current against time.
There are many different values associated with an AC sine wave but the one that continually changes throughout the cycle is the instantaneous value.
Hence, the correct option is A.
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Suppose we have 999 records of employees Emp1, Emp2, Emp5, Emp6 and so on up to Emp998 and Emp999 stored in a sequence. Hence, records are nothing but a row in the table. In the employee table, we want to insert new records Emp3 and Emp4 in the sequence, and once we have done insertion we need to update and retrieve the record efficiently to optimize the performance of a database by minimizing the access time when query is being executed.
The records in the table represents the employee ID of each employee. Assume the table name is EMPLOYEES and the field name of employee IDs is ID, the following SQL query inserts Emp3 and Emp4 into the employees table.
INSERT INTO EMPLOYEES (ID) values (Emp3), (Emp4)
The complete question requires that we list the pros and cons of solving the problem using Index sequential access method (ISAM).
The advantage of using ISAM is that priorities are given to the indices of the records being inserted. So, Emp3 and Emp4 will be inserted immediately after Emp2.
However, a major disadvantage of using ISAM is that it is very expensive to keep the indices in a sequential order;
See attachment for the illustration of Index sequential access method (ISAM).
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There are some sections of the SDS that are not mandatory
True or false
Answer:
True
Explanation:
There are 16 in all and 4 are not mandatory
There are some sections of the SDS that are not mandatory. Thus, option A is correct.
What is SDS?A Safety Data Sheet, previously known as a Material Safety Data Sheet, is a thorough instructional report written by a dangerous product's producer or exporter. It gives a description of something like the product's chemical and physical characteristics.
Sections 1 through 11 and 16 must be used; sections 12 through 15 are optional but could be included. the section which will are not compulsory are:
Section 12: Environmental data
Section 13: Guidelines for Recycling
Section 14: Documentation regarding mobility
Section 15: Relevant data about regulations
In Safety Data Sheet, all the sections are not compulsory or mandatory. this statement is true. Therefore, option A is the correct option.
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Side milling cutter is an example of ______ milling cutter.
Answer:
special type
Explanation:
As per the classification of milling cutters. This cutter can handle deep and long open slots in a more comfortable manner, which increase the productivity.
answer this qustion plz
Answer:
click here and I'm so happy I have been doing this weekend I can see the same way you could come back in a bit and then we are all of you to know you do for a bit of time with me or
Which tool is used to measure movement automotive
Answer:
Speedometer
It shows our speed, or how fast we're moving.
The end of the industrial robotic arm extends along the path (r = 2 + 2 cos (5t)) m. At the instant ( 0 = 0.8t ) radians. When the arm is located at (t = 0.85) second Determine the velocity and acceleration of the object A at this instant.
Answer:
v = 8.95 rad / s, a = 22.3 rad / s²
Explanation:
This is an exercise in kinematics, where we must use the definitions of velocity and acceleration
v = dr / dt
we perform the derivative
v = 0+ 2 (-sin 5t) 5
v = -10 sin 5t
we calculate for t = 0.85 t,
remember angles are in radians
v = -10 sin (5 0.85)
v = 8.95 rad / s
acceleration is defined by
a = dv / dt
we perform the derivatives
a = -10 (cos 5t) 5
a = - 50 cos 5t
we calculate for t = 0.85 s
a = -50 are (5 0.85)
a = 22.3 rad / s²
The base of an aluminum block, which is fixed in place, measures 90 cm by 90 cm, and the height of the block is 60 cm. A force, applied to the upper face and parallel to it, produces a shear strain of 0.0060. The shear modulus of aluminum is . What is the displacement of the upper face in the direction of the applied force
The question is incomplete. The complete question is :
The base of an aluminum block, which is fixed in place, measures 90 cm by 90 cm, and the height of the block is 60 cm. A force, applied to the upper face and parallel to it, produces a shear strain of 0.0060. The shear modulus of aluminum is [tex]3.0 \times 10^{10} \ Pa[/tex] . What is the displacement of the upper face in the direction of the applied force?
Solution :
The relation between shear modulus, shear stress and strain,
[tex]$\text{Shear modulus, S =} \frac{\text{Shear stress}}{\text{shear strain}}$[/tex]
Shear stress = shear modulus (S) x shear strain
[tex]$=3 \times 10^{10} \times 0.0060$[/tex]
[tex]$=1.80 \times 10^8$[/tex] Pa
[tex]$=180 \times 10^6$[/tex] Pa
[tex]$=180 \ MPa$[/tex]
The length represents the distance between the fixed in place portion and where the force is being applied.
Therefore,
[tex]$\text{Displacement} = \text{shear strain} \times \text{length}$[/tex]
= 0.006 x 60 cm
= 0.360 cm
= 3.6 mm
Thus, the displacement of the upper face is 3.6 mm in the direction of the applied force.
Hydraulic fracturing is: Select one: a. a first step in storage of high-level radioactive waste b. a way of extracting natural gas shale formations c. a step in oil refining where oil is separated into different viscosities d. none of the above
Shale and other types of "tight" rock, or impermeable rock formations that lock in oil and gas and complicate the production of fossil fuels, can be extracted of their natural gas or oil using the modern high-volume hydraulic fracturing process. Thus, option B is correct.
What are the factor involving in Hydraulic fracturing?Shale gas is extracted through a procedure called hydraulic fracturing, also referred to as “fracking.” Due to the fact that shale reserves are often dispersed horizontally rather than vertically, deep holes are first drilled into the shale rock, then horizontal drilling is used to reach more of the gas.
A mixture of sand, chemicals, and water is pushed at high pressure down a borehole during hydraulic fracturing. The released gas can flow out of the rocks and back up the borehole because the water pressure causes cracks in the rock to widen, and the sand particles settle into the openings to keep them open.
Therefore, a way of extracting natural gas shale formations.
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If a corporation is socially responsible, it will develop and implement a sustainability plan and communicate it to stakeholders.
True
False
Answer:
True
Explanation:
All big companies are pretty much required in today's day and ages to complete these reports whether they truly believe it.
số bit của pic 16f887
Answer:
what does it mean
Explanation:
sorry
plz write in English
What is the following diagram called?
Answer:
business
Explanation:
because shopping has great income
Answer:
is ur question right
Explanation:
is ur question right
is ur question right
Troy must keep track of the amount of refrigerant he uses from a 50-pound cylinder to ensure that accurate
records are kept. He used 13 pounds on a systein for Ms. Jones and 9 pounds on a system for a commercial
client. How many pounds should he have left in the cylinder?
tof
Troy should have
pounds of refrigerant left in the cylinder.
baon naid Thamar basic
محمود احمد مجد
12
اهداء ما در
Answer:
Amount of gas still in cylinder = 28 pound
Explanation:
Given:
Amount of gas in cylinder = 50 pound
Amount of gas used in Ms. Jones system = 13 pound
Amount of gas used in client system = 9 pound
Find:
Amount of gas still in cylinder
Computation:
Amount of gas still in cylinder = Amount of gas in cylinder - Amount of gas used in Ms. Jones system - Amount of gas used in client system
Amount of gas still in cylinder = 50 - 13 - 9
Amount of gas still in cylinder = 28 pound
What is the following diagram called?
Answer:
flow chart
Explanation:
it's a flow chart right ? don't know the explanation cause I am not even sure I am right
Uses of P-N junction
Answer:
Explanation:
Two that come to mind:
a semiconductor diode is essentially a PN junctiona transistor is made of two pn junctions.A steam turbine generator unit is used to produce electricity, where steam enters the turbine with a velocity of 30 m/s and enthalpy (internal energy) of 3348 kJ/kg. The 1 steam leaves the turbine as a mixture of vapor and liquid having a velocity of 60 m/s and an enthalpy of 2550 kJ/kg. The flow through the turbine is adiabatic, and changes in elevation are negligible. Determine the work output from the turbine, if the mass flow rate is 5kg/s.
Answer:
3.983 MW
Explanation:
Given that:
At the inlet:
Velocity (v₁) = 30 m/s
Enthalpy (h₁) = 3348 kJ/kg
At the outlet:
Velocity (v₂) = 60 m/s
Enthalpy (h₂) = 2550 kJ/kg
Mass flow rate (m) = m₁ = m₂ = 5kg/s
According to the steady flow energy equation:
[tex]Q+ m_1 (h_1 + \dfrac{v_1^2}{2000}+ \dfrac{gz_1}{1000} )= m_2(h_2+\dfrac{v_2^2}{2000}+\dfrac{gz_2}{1000})+W_{shaft}[/tex]
Since the elevation (z) is negligible and flow via the turbine is adiabatic:
Then,
Q = 0 and z₁ = z₂
∴
[tex]W_{shaft} = (mh_1-mh_2) + (\dfrac{mv_1^2-mv_2^2}{2000})[/tex]
[tex]W_{shaft} = ((5*3348) -(5*2550)) + (\dfrac{(5*(30)^2)-(5*(60)^2)}{2000})[/tex]
[tex]W_{shaft} = (16740-12750) + (\dfrac{4500-18000}{2000})[/tex]
[tex]W_{shaft} = (16740-12750) + (-6.75)[/tex]
[tex]W_{shaft} = 3983.25 \ kW[/tex]
[tex]\mathbf{W_{shaft} = 3.983 \ MW}[/tex]
A mechanic claims to have developed a car engine that runs on water instead of gasoline. What is your response to this claim?
The claim will be impractical. The reason behind this is provided below throughout the explanation segment.
Inside the same combustion chamber, fresh water can't be pressurized even more than fuel as well as air. Consequently, the cylinder does not burn due to a problem with the compressor.To accomplish the development processes, a machine requires any sort of combustible which might cause combustion as well as create a tremendous quantity of power.
Thus, the idea of using water instead of petroleum appears unworkable throughout traditional engines.
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which type of clectrical circuit is represented by this diagram?
Answer:
parallel
Explanation:
All components in this circuit are tied in parallel. Each component experiences the same voltage from one terminal to the other. It is a parallel circuit.
if a person is injured at the hospital during a natural disaster a correct action to take is
Why is logging done during drilling?
Answer:
Logging while drilling (LWD) is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly (BHA). ... In these situations, the LWD measurement ensures that some measurement of the subsurface is captured in the event that wireline operations are not possible
You are given a pot of hot tea (350 mL) at a temperature of 85°C and a quantity of ice at -12°C. Determine the absolute minimum amount of ice you can add to the hot tea so that at equilibrium you have iced tea (ie. a very, very small amount of ice and some water). You can assume tea has the same density (1.00 g/mL) and specific heat (4190 J/kgK) as liquid water. The heat of fusion of H2O is 3.33x10^5 J/kg. The specific heat of ice is 2090 J/kgK.
Answer:
348 g
Explanation:
The heat gained by the ice equals the heat lost by the hot tea.
Also, since we require a very, very small amount of ice and some water, to still have some ice, the temperature of the hot tea has to decrease to the melting point of ice which is 0°C. So, the final temperature of the mixture is 0 °C.
So, mc(T - T') + mL = -MC(T - T") where m = mass of ice, c = specific heat of ice = 2090 J/kgK., T = final temperature of mixture = 0 °C, T' = initial temperature of ice = -12 °C, L = heat of fusion of H2O = 3.33 × 10⁵ J/kg, M = mass of hot tea = ρV where ρ = density of tea = 1.00 g/mL and V = volume of hot tea = 350 mL. So, M = ρV = 1.00 g/mL × 350 mL = 350 g = 0.350 kg, C = specific heat of tea = 4190 J/kgK and T" = initial temperature of tea = 85 °C.
Making m subject of the formula, we have
mc(T - T') + mL = -MC(T - T")
m[c(T - T') + L] = -MC(T - T")
m = -MC(T - T")/[c(T - T') + L]
substituting the values of the variables into the equation, we have
m = -MC(T - T")/[c(T - T') + L]
m = -0.350 kg × 4190 J/kgK(0 °C - 85 °C.)/[2090 J/kgK(0 °C. - (-12 °C)) + 3.33 × 10⁵ J/kg]
m = -1466.5 J/kK(- 85 °C)/[2090 J/kgK(0 °C + 12 °C)) + 3.33 × 10⁵ J/kg]
m = 124652.5 J/[2090 J/kgK(12 °C) + 3.33 × 10⁵ J/kg]
m = 124652.5 J/[25080 J/kg + 3.33 × 10⁵ J/kg]
m = 124652.5 J/358080 J/kg
m = 0.3481 kg
m = 348.1 g
m ≅ 348 g
So, the minimum amount of ice to be added is 348 g.
Work to be performed can come from the work package level of the work breakdown structure as well as other sources. Which of these is NOT a source of authorized work to be performed?
a. Scope creep
b. Defect repairs
c. Preventive actions
d. Corrective actions
A project is meant to achieve clearly defined goals within present constraints
The correct option for the source of work in a project which is NOT a source of authorized work to be performed is option (a)
a. Scope creep
The reason for the selecting the above option is as follows;
In project management, alongside work planned in a work package, authorized work to be performed can come from;
The repairing of defects found in completed work and which is a requirement for the project to be approvePreventive actions, that are meant to mitigate factors that affect the project timeline and costCorrective actions which include actions meant to rectify parts of the project that produce an error outcomeA scope creep, however, is generally is due to the inclusion of the end
users of the project at a time that is behind schedule, insufficient analysis of
the requirements, and project complexity underestimation. and consists of
changes made after a project has commenced
A scope creep therefore, changes the amount of work to be done which
therefore alters the project timeline, and due to project, budgetary, and
end user constraints, CANNOT be a source of authorized work to be
performed
The correct option for the source that is NOT a authorized work to be performed is option a. Scope creep
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anxiety: a. is never normal. b. is common of many psychological disorders c. is identical to fear d. is a modern development, unlikely to have roots in human history
Answer:
B
Explanation:
Anxiety is very common especially nowadays but it's especially common in psychological disorders
an atom that gained an electron is called
Answer:
Hey mate......
Explanation:
This is ur answer.....
When an atom gains/loses an electron, the atom becomes charged, and is called an ion.Hope it helps!
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beacuse thye want them to hav egoood and thye wn thme tto
Answer:
I don't understand the question
. Bơm kiểu piston tác dụng đơn có áp suất p=0,64 Mpa và lưu lượng Q=3,5 l/s. Xác định tốc độ quay của trục bơm và công suất của bơm nếu biết đường kính piston D=150 mm; bán kính tay quay R=60 mm; hiệu suất thể tích của bơm là 0=0,94; hiệu suất chung của bơm b=0,80.
Answer:
not understand language
True or false: You can create a network with two computers.
Answer
True
Explain the 11 sections that a typical bill of quantity is divided into
Answer:
The main sections included in the bill of quantities are Form of Tender, Information, Requirements, Pricing schedule, Provisional sums, and Day works.
Which of the following conditions were present in over 80% of paddling fatalities from 1995-2000?
Answer:
80% of the people that were killed weren't wearing a safety flotation device ( in correct terminology Personal Flotation Device, or PFD )
Explanation:
Hence they drowned due to the lack of safety.
The condition present in over 80% of paddling fatalities is that the victims were said to be not wearing a personal flotation device (PFD).
What is paddling in the sea?The act of paddling is known to be a sport or something one can do for fun or for games.
Conclusively, a lot of paddling fatalities 1995-2000 was due to the fact that the people who were engage in the sport or act were not putting on a personal flotation device (PFD) and this can lead to death or drowning.
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what is the best book for mechanic of materials?
Answer:
As per my experience Egor Popov is one the best book for mechanics of materials.
Explanation:
hope this helps
