A 4-pole, 3-phase induction motor operates from a supply whose frequency is 60 Hz. calculate: 1- the speed at which the magnetic field of the stator is rotating

Answers

Answer 1

Answer:

Answer:

The answer is below

Explanation:

A 4-pole, 3-phase induction motor operates from a supply whose frequency is 60 Hz. calculate: 1- the speed at which the magnetic field of the stator is rotating. 2- the speed of the rotor when the slip is 0.05. 3- the frequency of the rotor currents when the slip is 0.04. 4- the frequency of the rotor currents at standstill.

Given that:

number of poles (p) = 4, frequency (f) = 60 Hz

1) The synchronous speed of the motor is the speed at which the magnetic field of the stator is rotating. It is given as:

$n_s=(120f)/(p)=(120*60)/(4)=1800\ rpm$

2) The slip (s) = 0.05

The speed of the motor (n) is the speed of the rotor, it is given as:

$n=n_s-sn_s\n\nn=1800-0.05(1800)\n\nn=1800-90\n\nn=1710\ rpm$

3) s = 0.04

The rotor frequency is the product of the supply frequency and slip it is given as:

$f_r=sf\n\nf_r=0.04*60\n\nf_r=2.4\ Hz$

4) At standstill, the motor speed is zero hence the slip = 1:

$s=(n_s-n)/(n_s)\n \nn=0\n\ns=(n_s-0)/(n_s)\n\ns=1$

The rotor frequency is the product of the supply frequency and slip it is given as:

$f_r=sf\n\nf_r=1*60\n\nf_r=60\ Hz$

Related Questions

In the hydrodynamic entrance region of a pipe with a steady flow of an incompressible liquid A. The average velocity increases with distance from the entrance. B. The average velocity stays the same with distance from the entrance. C. The maximum velocity increases with distance from the entrance. D. The maximum velocity decreases with distance from the entrance. E. B and C F. B and D
A hot brass plate is having its upper surface cooled by impinging jet of air at temperature of 15°C and convection heat transfer coefficient of 220 W/m^2•K. The 10-cm thick brass plate (rho = 8530 kg/m^3, cp = 380 J/kg•K, k = 110 W/m•K, and α = 33.9×10^–6 m^2/s) has a uniform initial temperature of 900°C, and the bottom surface of the plate is insulated. Required:Determine the temperature at the center plane of the brass plate after 3 minutes of cooling.
Write a C++ program to display yearly calendar. You need to use the array defined below in your program. // the first number is the month and second number is the last day of the month. into yearly[12][2] =
A refrigeration system was checked for leaks. The system temperature and surroundings were 75°F when the system was charged with nitrogen to 100 psig. The temperature then dropped to 50°F. What should the pressure be if no nitrogen has escaped?A) 9 psigB) 94 psigC) 100 psigD) 90 psig
_________ items are similar to the free issue items, but their access is limited. (CLO5) a)-Bin stock items free issue b)-Bin stock controlled issue c)-Critical or insurance spares d)-Rebuildable spares e)-consumables

Determine the boundary work done by a gas during an expansion process if the pressure and volume values at various states are measured to be 300 kPa, 1 L; 290 kPa, 1.1 L; 270 kPa, 1.2 L; 250 kPa, 1.4 L; 220 kPa, 1.7 L; and 200 kPa, 2 L

Answers

By Riemann sums, the boundarywork done by a gas during an expansionprocess based on the information given by the statement is approximately 0.243 joules.

How to determine the boundary work done by a gas during an expansion process

A process is a consecution of states of a system. The boundary work (W), in kilojoules, is the work done by the system on surroundings and in a P-Vdiagram this kind of work is equal to the area below the curve, which can be approximated by Riemann sums:

$W = \sum\limits_(i=1)^(n-1) p_(i)\cdot (V_(i+1)-V_(i)) + (1)/(2)\sum\limits_(i=1)^(n-1) (p_(i+1)-p_(i))\cdot (V_(i+1)-V_(i))$ (1)

Where:

p - Pressure, in kilopascals.
V - Volume, in cubic meters.

$W = (1)/(2) \sum\limits_(i=1)^(n-1) (p_(i+1)+p_(i))\cdot (V_(i+1)-V_(i))$

Now we proceed to calculate the boundary work:

W = 0.5 · [(300 kPa + 290 kPa) · (1.1 × 10⁻³ m³ - 1 × 10⁻³ m³) + (270 kPa + 290 kPa) · (1.2 × 10⁻³ m³ - 1.1 × 10⁻³ m³) + (250 kPa + 270 kPa) · (1.4 × 10⁻³ m³ - 1.2 × 10⁻³ m³) + (220 kPa + 250 kPa) · (1.7 × 10⁻³ m³ - 1.4 × 10⁻³ m³) + (200 kPa + 220 kPa) · (2 × 10⁻³ m³ - 1.7 × 10⁻³ m³)]

W = 0.243 kJ

By Riemann sums, the boundarywork done by a gas during an expansionprocess based on the information given by the statement is approximately 0.243 joules.

To learn more on boundary work, we kindly invite to check this: brainly.com/question/17136485

#SPJ2

Answer:

attached below

Explanation:

A 2-m3insulated rigid tank contains 3.2 kg of carbon dioxide at 120 kPa.Paddle-wheel work is done on the system until the pressure in the tank rises to 180kPa. Determine the entropy change in the carbon dioxide during this process. Assumeconstant specific heat and room temperature at 300 K

Answers

Answer:

The change in entropy is found to be 0.85244 KJ/k

Explanation:

In order to solve this question, we first need to find the ration of temperature for both state 1 and state 2. For that, we can use Charles' law. Because the volume of the tank is constant.

P1/T1 = P2/T2

T2/T1 = P2/P1

T2/T1 = 180 KPa/120KPa

T2/T1 = 1.5

Now, the change in entropy is given as:

ΔS = m(s2 - s1)

where,

s2 = Cv ln(T2/T1)

s1 = R ln(V2/V1)

ΔS = change in entropy

m = mass of CO2 = 3.2 kg

Therefore,

ΔS = m[Cv ln(T2/T1) - R ln(V2/V1)]

Since, V1 = V2, therefore,

ΔS = mCv ln(T2/T1)

Cv at 300 k for carbondioxide is 0.657 KJ/Kg.K

Therefore,

ΔS = (3.2 kg)(0.657 KJ/kg.k) ln(1.5)

ΔS = 0.85244 KJ/k

How do we use the brakes in the airplane?

Answers

Answer:

When a pilot pushes the top of the right pedal, it activates the brakes on the right main wheel/wheels, and when the pilot pushes the top of the left rudder pedal, it activates the brake on the left main wheel/wheels. The brakes work in a rather simple way: they convert the kinetic energy of motion into heat energy.

Explanation:

For a steel alloy it has been determined that a carburizing heat treatment of 11-h duration will raise the carbon concentration to 0.38 wt% at a point 2.3 mm from the surface. Estimate the time (in h) necessary to achieve the same concentration at a 5.3 mm position for an identical steel and at the same carburizing temperature.

Answers

Answer:

Time =t2=58.4 h

Explanation:

Since temperature is the same hence using condition

x^2/Dt=constant

where t is the time as temperature so D also remains constant

hence

x^2/t=constant

2.3^2/11=5.3^2/t2

time=t^2=58.4 h

The cost of hiring new employees outpaces the raises for established employees is A.
Salary compression

B.
Occupational based pay

C.
Merit pay

D.
Need for Achievement

Answers

Answer:

do you have to make the right decisions to be a person who has been a member who is not the first time a great person who has a job in a day of his life or

"Given a nodal delay of 84.1ms when there is no traffic on the network (i.e. usage = 0%), what is the effective delay when network usage = 39.3% ? (Give answer is miliseconds, rounded to one decimal place, without units. So for an answer of 0.10423 seconds you would enter "104.2" without the qu"

Answers

Answer:

Explanation:

effective delay = delay when no traffic x $(100)/(100- network\r usage)$

effective delay = $84.1 * (100)/(100-39.3)=138.55024711697ms$

Other Questions

Calculate the angle of banking on a bend of 100m radius so that vehicles can travel round the bend at 50km/hr without side thrust on the tyres.

Can anyone tell me all the corrects answers to these? I’m sorry if this is the wrong subject I’m not sure what to put it under but I really need help!

can anyone help me with this please.i have the current and pf for branch 1 and 2 but cant figure out the total current, pf and angle. thanks

A furnace is shaped like a long equilateral triangular duct where the width of each side is 2 m. Heat is supplied from the base surface, whose emissivity is ε1 = 0.8, at a rate of 800 W/m2 while the side surfaces, whose emissivities are 0.5, are maintained at 500 K. Neglecting the end effects, determine the temperature of the base surface. Can you treat this geometry as a two-surface enclosure?