A 15-hp, 220-V, 2000-rpm separately excited dc motor controls a load requiring a torque of 147 , the armature 45 N·m at a speed of 1200 rpm. The field circuit resistance is Rf TL circuit resistance is Ra The field voltage is Vf 0.25 , and the voltage constant of the motor is K₂ 220 V. The viscous friction and no-load losses are negligible. The arma- ture current may be assumed continuous and ripple free. Determine (a) the back emf Eg, (b) the required armature voltage Va, and (c) the rated armature current of the motor. Solution = = = = = = 0.7032 V/A rad/s.

Answers

Answer 1

(a) The back emf (Eg) of the motor is 0.7032 V/A rad/s.

(b) The required armature voltage (Va) for the motor is to be determined.

(c) The rated armature current of the motor needs to be calculated.

To determine the back emf (Eg), we can use the formula Eg = K₂ * ω, where K₂ is the voltage constant of the motor and ω is the angular velocity. Given that K₂ is 220 V and ω is 2000 rpm (converted to rad/s), we can calculate Eg as 0.7032 V/A rad/s.

To find the required armature voltage (Va), we need to consider the torque and back emf. The torque equation is T = Kt * Ia, where T is the torque, Kt is the torque constant, and Ia is the armature current. Rearranging the equation, we get Ia = T / Kt. Since the load requires a torque of 147 N·m and Kt is related to the motor characteristics, we would need more information to calculate Va.

To determine the rated armature current, we can use the formula V = Ia * Ra + Eg, where V is the terminal voltage, Ra is the armature circuit resistance, and Eg is the back emf. Given that V is 220 V and Eg is 0.7032 V/A rad/s, and assuming a continuous and ripple-free armature current, we can calculate the rated armature current. However, the given values for Ra and other necessary parameters are missing, making it impossible to provide a specific answer for the rated armature current.

Learn more about back emf here

brainly.com/question/13109636

#SPJ11


Related Questions

determine the clearance for blanking 3in square blanks in .500in steel with a 10 llowence

Answers

Clearance for blanking 3 in square blanks in 0.500 in steel with a 10 % allowance:

What is blanking?

Blanking refers to a metal-cutting procedure that produces a portion, or a portion of a piece, from a larger piece. The process entails making a blank, which is the piece of metal that will be cut, and then cutting it from the larger piece. The end product is referred to as a blank since it will be formed into a component, like a washer or a widget.

What is clearance?

Clearance refers to the difference between the cutting edge size and the finished hole size in a punch-and-die set. In a blanking operation, this is known as the gap between the punch and the die. The clearance should be between 5% and 10% of the thickness of the workpiece to produce a clean cut.

For steel thicknesses of 0.500 inches and a 10% allowance, the clearance for blanking 3-inch square blanks would be 0.009 inches (0.5 inches x 10% / 2).

Thus, the clearance for blanking 3 in square blanks in 0.500 in steel with a 10 % allowance will be 0.009 inches.

Learn more about blanking: https://brainly.com/question/16684227

#SPJ11

A cylinder with a movable piston contains 5.00 liters of a gas at 30°C and 5.00 bar. The piston is slowly moved to compress the gas to 8.80bar. (a) Considering the system to be the gas in the cylinder and neglecting ΔEp, write and simplify the closed-system energy balance. Do not assume that the process is isothermal in this part. (b) Suppose now that the process is carried out isothermally, and the compression work done on the gas equals 7.65L bar. If the gas is ideal so that ^ U is a function only of T, how much heat (in joules) is transferred to or from (state which) thes urroundings? (Use the gas-constant table in the back of the book to determine the factor needed to convert Lbar to joules.)(c) Suppose instead that the process is adiabatic and that ^ U increases as T increases. Is the nal system temperature greater than, equal to, or less than 30°C? (Briey state your reasoning.)

Answers

A cylinder with a movable piston contains 5.00 liters of a gas at 30°C and 5.00 bar. The piston is slowly moved to compress the gas to 8.80bar.

(a) The closed-system energy balance can be written as follows:ΔU = Q − W, where ΔU is the change in internal energy, Q is the heat transferred to the system, and W is the work done by the system. Neglecting ΔEp, the work done by the system is given by W = PΔV, where P is the pressure and ΔV is the change in volume. Therefore, ΔU = Q − PΔV.

(b) Since the process is carried out isothermally, the temperature remains constant at 30°C. Therefore, ΔU = 0. The work done by the system is

W = −7.65 L bar, since the compression work is done on the gas. Using the gas constant table, we find that 1 L bar = 100 J. Therefore, the work done by the system is

W = −7.65 L bar × 100 J/L bar = −765 J. Since

ΔU = 0, we have Q = W = −765 J. The heat is transferred from the system to the surroundings.

(c) Since the process is adiabatic, Q = 0. Therefore, the closed-system energy balance simplifies to ΔU = −W. Since the gas is ideal and ^ U is a function only of T, the change in internal energy can be written as ΔU = (3/2)nRΔT, where n is the number of moles of gas, R is the gas constant, and ΔT is the change in temperature. Since ^ U increases as T increases, we have ΔU > 0. Therefore, ΔT > 0, and the final system temperature is greater than 30°C.

Learn more about closed-system among others here: https://brainly.com/question/2846657

#SPJ11

Develop a minimum-multiplier realization of a length-7 Type 3 Linear Phase FIR Filter.

Answers

A minimum-multiplier realization of a length-7 Type 3 Linear Phase FIR Filter can be developed.

To develop a minimum-multiplier realization of a length-7 Type 3 Linear Phase FIR Filter, we need to understand the key components and design considerations involved. A Type 3 Linear Phase FIR Filter is characterized by its linear phase response, which means that all frequency components of the input signal experience the same constant delay. The minimum-multiplier realization aims to minimize the number of multipliers required in the filter implementation, leading to a more efficient design.

In this case, we have a length-7 filter, which implies that the filter has 7 taps or coefficients. Each tap represents a specific weight or gain applied to a delayed version of the input signal. To achieve a minimum-multiplier realization, we can exploit the symmetry properties of the filter coefficients.

By carefully analyzing the symmetry properties, we can design a structure that reduces the number of required multipliers. For a length-7 Type 3 Linear Phase FIR Filter, the minimum-multiplier realization can be achieved by utilizing symmetric and anti-symmetric coefficients. The symmetric coefficients have the same value at equal distances from the center tap, while the anti-symmetric coefficients have opposite values at equal distances from the center tap.

By taking advantage of these symmetries, we can effectively reduce the number of multipliers needed to implement the filter. This results in a more efficient and resource-friendly design.

Learn more about multiplier

brainly.com/question/31406180

#SPJ11

8. Write and execute a query that will delete all countries that are not assigned to an office or a client. You must do this in a single query to receive credit for this question. Write the delete query below and then execute the following statement in SQL Server: Select * from Countries. Take a screenshot of your select query results and paste them below your delete query that you constructed.

Answers

The Countries which are not assigned any Office means that the values are Null or Blank:

I created a table:

my sql> select*from Country; + | Country Name | Office | - + | Yes | NULL | Yes | Croatia | Argentina Sweden Brazil Sweden | Au

Here in this table there is Country Name and a Office Column where it is Yes, Null and Blank.

So, we need to delete the Blank and Null values as these means that there are no office assigned to those countries.

The SQL statement:

We will use the delete function,

delete from Country selects the Country table.

where Office is Null or Office = ' ' ,checks for values in Office column which are Null or Blank and deletes it.

Code:

mysql> delete from Country     -> where Office is Null or Office = ''; Query OK, 3 rows affected (0.01 sec)

Code Image:

mysql> delete from Country -> where Office is Null or Office Query OK, 3 rows affected (0.01 sec) =

Output:

mysql> select*from Country; + | Country Name | Office | + | Croatia Sweden Sweden | India | Yes | Yes Yes | Yes + 4 rows in s

You can see that all the countries with Null and Blank values are deleted

Which of the followings is true? Given an RC circuit: resistor-capacitor C in series. The output voltage is measured across C, an input voltage supplies power to this circuit. For the transfer function of the RC circuit with respect to input voltage: O A. Its phase response is -90 degrees. O B. Its phase response is negative. O C. Its phase response is 90 degrees. O D. Its phase response is positive.

Answers

In an RC circuit with a resistor-capacitor in series and the output voltage measured across C while an input voltage supplies power to this circuit, the phase response of the transfer function of the RC circuit with respect to input voltage is -90 degrees.

Hence, the correct answer is option A. A transfer function is a mathematical representation of a system that maps input signals to output signals.The transfer function of an RC circuit refers to the voltage across the capacitor with respect to the input voltage. The transfer function represents the system's response to the input signals.

The transfer function H(s) of the RC circuit with respect to input voltage V(s) is given by the equation where R is the resistance, C is the capacitance, and s is the Laplace operator. In the frequency domain, the transfer function H(jω) is obtained by substituting s = jω where j is the imaginary number and ω is the angular frequency.A phase response refers to the behavior of a system with respect to the input signal's phase angle. The phase response of the transfer function H(jω) for an RC circuit is given by the expression.

To know more about resistor-capacitor visit :

https://brainly.com/question/31080064

#SPJ11

please need answer asap
5 5. An aircraft is moving steadily in the air at a velocity of 330 m/s. Determine the speed of sound and Mach number at (a) 300 K (4 marks) (b) 800 K. (4 marks)

Answers

The speed of sound can be calculated using the equation v = √(γRT), where v is the speed of sound, γ is the adiabatic index (1.4 for air), R is the gas constant (approximately 287 J/kg*K), and T is the temperature in Kelvin.

(a) At 300 K, the speed of sound can be calculated as v = √(1.4 * 287 * 300) = 346.6 m/s. To find the Mach number, we divide the velocity of the aircraft (330 m/s) by the speed of sound: Mach number = 330/346.6 ≈ 0.951.

(b) At 800 K, the speed of sound can be calculated as v = √(1.4 * 287 * 800) = 464.7 m/s. The Mach number is obtained by dividing the velocity of the aircraft (330 m/s) by the speed of sound: Mach number = 330/464.7 ≈ 0.709.

The speed of sound can be calculated using the equation v = √(γRT), where v is the speed of sound, γ is the adiabatic index (1.4 for air), R is the gas constant (approximately 287 J/kg*K), and T is the temperature in Kelvin. For part (a), at a temperature of 300 K, substituting the values into the equation gives v = √(1.4 * 287 * 300) = 346.6 m/s. To find the Mach number, which represents the ratio of the aircraft's velocity to the speed of sound, we divide the given velocity of the aircraft (330 m/s) by the speed of sound: Mach number = 330/346.6 ≈ 0.951. For part (b), at a temperature of 800 K, substituting the values into the equation gives v = √(1.4 * 287 * 800) = 464.7 m/s. The Mach number is obtained by dividing the given velocity of the aircraft (330 m/s) by the speed of sound: Mach number = 330/464.7 ≈ 0.709.

Learn more about Mach number here

brainly.com/question/29538118

#SPJ11

Prove that a Schmitt oscillator trigger can work as a VCO.

Answers

Step 1:

A Schmitt oscillator trigger can work as a VCO (Voltage Controlled Oscillator).

Step 2:

A Schmitt oscillator trigger, also known as a Schmitt trigger, is a circuit that converts an input signal with varying voltage levels into a digital output with well-defined high and low voltage levels. It is commonly used for signal conditioning and noise filtering purposes. On the other hand, a Voltage Controlled Oscillator (VCO) is a circuit that generates an output signal with a frequency that is directly proportional to the input voltage applied to it.

By incorporating a voltage control mechanism into the Schmitt trigger circuit, it can be transformed into a VCO. This can be achieved by introducing a variable voltage input to the reference voltage level of the Schmitt trigger. As the input voltage changes, it will cause the switching thresholds of the Schmitt trigger to vary, resulting in a change in the output frequency.

The VCO functionality of the modified Schmitt trigger circuit allows it to generate a continuous output signal with a frequency that can be controlled by the applied voltage. This makes it suitable for various applications such as frequency modulation, clock generation, and signal synthesis.

Step 3:

Learn more about : frequency

Describe frequency, relative frequency, and cumulative relative frequency.

#SPJ11

It is necessary to evacuate 49.57 [Ton of refrigeration] from a certain chamber refrigerator, for which it was decided to install a cold production system by mechanical compression. The chamber temperature cannot exceed –3[°C] and the temperature difference at the evaporator inlet is estimated at 7[°C].
You have a large flow of well water at 15[°C] that you plan to use as condensing agent. The refrigerant fluid used is R-134a.
For the operation of this installation, an alternative compressor was acquired. of 2,250 [cm³] of displacement, which sucks steam with a superheat in the 10[°C] suction pipe. This compressor rotates at 850[r.p.m.] and its volumetric efficiency is 0.8 for a compression ratio of 3.3.
Calculate the degree of subcooling of the condensed fluid so that it can
operate the installation with this compressor and if it is possible to carry it out.
Note: Consider a maximum admissible jump in the well water of 5[°C] and a minimum temperature jump in the condenser (between refrigerant fluid and water
of well) of 5[°C].

Answers

The degree of subcooling is 28°C, which is within the range of possible values for the system to operate.

The degree of subcooling is the difference between the temperature of the condensed refrigerant and the saturation temperature at the condenser pressure. A higher degree of subcooling will lead to a lower efficiency, but it is possible to operate the system with a degree of subcooling of 28°C. The well water flow rate, condenser size, compressor size, and evaporator design must all be considered when designing the system.

The degree of subcooling is important because it affects the efficiency of the system. A higher degree of subcooling will lead to a lower efficiency because the refrigerant will have more energy when it enters the expansion valve. This will cause the compressor to work harder and consume more power.

The well water flow rate must be sufficient to remove the heat from the condenser. If the well water flow rate is too low, the condenser will not be able to remove all of the heat from the refrigerant and the system will not operate properly.

The condenser must be sized to accommodate the well water flow rate. If the condenser is too small, the well water will not be able to flow through the condenser quickly enough and the system will not operate properly.

The compressor must be sized to handle the refrigerant mass flow rate. If the compressor is too small, the system will not be able to cool the chamber properly.

The evaporator must be designed to provide the desired cooling capacity. If the evaporator is too small, the system will not be able to cool the chamber properly.

It is important to consult with a refrigeration engineer to design a system that meets your specific needs.

Learn more about condenser pressure here:

https://brainly.com/question/32891465

#SPJ11

7. write and execute a query that will remove the contract type ""time and materials"" from the contracttypes table.

Answers

To remove the contract type "time and materials" from the contracttypes table, you can use a SQL query with the DELETE statement. Here's a brief explanation of the steps involved:

1. The DELETE statement is used to remove specific rows from a table based on specified conditions.

2. In this case, you want to remove the contract type "time and materials" from the contracttypes table.

3. The query would be written as follows:

  ```sql

  DELETE FROM contracttypes

  WHERE contract_type = 'time and materials';

  ```

  - DELETE FROM contracttypes: Specifies the table from which rows need to be deleted (contracttypes table in this case).

  - WHERE contract_type = 'time and materials': Specifies the condition that the contract_type column should have the value 'time and materials' for the rows to be deleted.

4. When you execute this query, it will remove all rows from the contracttypes table that have the contract type "time and materials".

It's important to note that executing this query will permanently delete the specified rows from the table, so it's recommended to double-check and backup your data before performing such operations.

Learn more about query:

https://brainly.com/question/25266787

#SPJ11

QUESTION 1 Which of the followings is true? Narrowband FM is considered to be identical to AM except O A. their bandwidth. O B. a finite and likely large phase deviation. O C. an infinite phase deviation. O D. a finite and likely small phase deviation.

Answers

Narrowband FM is considered to be identical to AM except in their bandwidth. In narrowband FM, a finite and likely small phase deviation is present. It is the modulation method in which the frequency of the carrier wave is varied slightly to transmit the information signal.

Narrowband FM is an FM transmission method with a smaller bandwidth than wideband FM, which is a more common approach. Narrowband FM is quite similar to AM, but the key difference lies in the modulation of the carrier wave's amplitude in AM and the modulation of the carrier wave's frequency in Narrowband FM.

The carrier signal in Narrowband FM is modulated by a small frequency deviation, which is inversely proportional to the carrier frequency and directly proportional to the modulation frequency. Therefore, Narrowband FM is identical to AM in every respect except the bandwidth of the modulating signal.

When the modulating signal is a simple sine wave, the carrier wave frequency deviates up and down about its unmodulated frequency. The deviation of the frequency is proportional to the amplitude of the modulating signal, which produces sidebands whose frequency is equal to the carrier frequency plus or minus the modulating signal frequency. 

To know more about modulation visit:

https://brainly.com/question/28520208

#SPJ11

Other Questions
1. The function \( f(x, y)=x^{2}+y^{2}-10 x-8 y+1 \) has one critical point. Find it, and determine if it is a local minimum, a local maximum, or a saddle point. Writing Equations Parallel and Perpendicular Lines.1. Find an equation of the line which passes through the point(4,3), parallel x=0 If a student inhales as deeply as possible and then blows the aire out until he cannot exhale anymorethe amount of air he expels is his? The list below are the target audience of an Automatic Pill Dispenser: - The Elderly people - The disabled people - The young children Why are these the target audience for an automatic pill dispenser? Explain one of the common errors in this experiment is overshooting the equivalence point. does this error cause an increase or decrease in the calculated mass percent? Explain the advantages and disadvantages of the 2 ray ground reflection model in the analysis of path loss. (b) In the following cases, tell whether the 2-ray model could be applied, and explain why or why not: h t=35 mh r=3 m,d=250 mh t=30 m,h r=1.5 md=450 m 5. Find the equation of the slant asymptote. Do not sketch the curve. \[ y=\frac{x^{3}-4 x-8}{x^{2}+2} \] 1) For any good (or service), a change in any factor except for ________ would shift the demand curveGroup of answer choicesThe weatherThe interest rateThe good's (own) selling priceAll of the above2) The upward slope that is typical of virtually all supply curves implies thatGroup of answer choicesThere is no clear relationship between price and quantity suppliedAs its price falls, the quantity supplied of a good will increaseAs its price rises, the quantity supplied of a good will increaseWe can predict how much of a good will be supplied, but only at the equilibrium price level3) If, for some reason, the current market price for a good is below its (true) equilibrium price, we would expect thatGroup of answer choicesbuyers for the good will start to outnumber sellers, which eventually forces the price back down towards equilibriumbuyers for the good will start to outnumber sellers, which eventually forces the price back up towards equilibriumsellers for the good will start to outnumber buyers, which eventually forces the price back down towards equilibriumsellers for the good will start to outnumber buyers, which eventually forces the price back up towards equilibrium4) Which of the following scenarios correctly illustrates the "indifference principle"?Group of answer choicesIf one business opportunity is much riskier than another, then eventually the riskier one will always produce lower returns (or profits)If two business opportunities are equally attractive in every possible way, then eventually they will produce basically identical returns (or profits)If one occupation (for example, garbage collection) is more difficult (or unpleasant) than most others, then eventually no one will be willing to perform that kind of work because it necessarily will pay very low wagesIn long-run equilibrium, people will decide what occupation to work in based only on the wages that the occupation pays, and not on account of any other factor Nadia wants to find out if students in her year like the school lunches. Shedecides to ask her class to complete a survey.Which of the statements below describes:ack to taska) the population?b) the sample?All the students in the schoolAll the students in Nadia's classAll the students in Nadia's yearAll the students not in Nadia's classAll the students not in Nadia's year How much does a price floor of $5 cost the government if it maintains the price floor by buying any surplus corn? **ANSWER BOTH PARTS FOR THIS QUESTION** A chronic alcoholic presents to the ER complaining of extreme abdominal pain and swelling, yellowing of skin, and worsening confusion. 1. Explain these three cl Sometimes covalent modifications are added to proteins in orderto make them functional; what is the name of this process? Give 3examples of such alterations List the four factors auditors should consider when evaluating the results of confirmation procedures. Also, what are three of the characteristics of a reliable confirmation? (For this and other questions, you may wish to refer relevant auditing standards). Describe the different effects of the two meals on satiety.Using the information from your lectures, what physiologicalmechanisms could drive these differences? In a nano-scale MOS transistor, which option can be used to achieve high Vt: a. Increasing channel length b. Reduction in oxide thickness c. Reduction in channel doping density d. Increasing the channel width e. Increasing doing density in the source and drain region calculate the number of moles of hi that are at equilibrium with 1.25 mol of h2 and 1.25 mol of i2 in a 5.00l flask at 448 c. h2 i2 2hi kc = 50.2 at 448 c Also known as the Great European Plain, the _____ has been an avenue for human migration time after time. A manufacturer of yeast finds that the culture grows exponentially at the rate of 13% per hour . a) if the initial mass is 3.7 , what mass will be present after: 7 hours and then 2 days Find the arc length function for the graph of \( f(x)=2 x^{3 / 2} \) using \( (0,0) \) as the starting point. What is the length of the curve from \( (0,0) \) to \( (4,16) \) ? Find the arc length fun When a firm determines the desired cost for a product or service, given a competitive market price, in order to earn a desired profit, the firm is exercising: Group of answer choices Target costing. Absorption costing. Variable costing. Competitive costing. Life cycle costing.