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LuckyWell [14K]
3 years ago
10

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
Engineering
1 answer:
rusak2 [61]3 years ago
4 0

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=\frac{120f}{p}=\frac{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=1800-0.05(1800)\\\\n=1800-90\\\\n=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\\\\f_r=0.04*60\\\\f_r=2.4\ Hz

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

s=\frac{n_s-n}{n_s}\\ \\n=0\\\\s=\frac{n_s-0}{n_s}\\\\s=1

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

f_r=sf\\\\f_r=1*60\\\\f_r=60\ Hz

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Explanation:

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Molar mass of N₂ = 28.0134 g/mol

Number of moles of H₂ = 500/2.01588  = 248 moles

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