Ask question

Ask question

All categories

bogdanovich [222]

3 years ago

12

A three-phase, 480 Volt, 120 horsepower, 50 Hertz four-pole induction motor delivers rated output power at a slip of 4%. Determi

ne the synchronous speed, the actual motor speed and the slip speed?

2 answers:

Bezzdna [24]3 years ago

8 0

Answer:

Explanation:

Given:

Number of poles, np = 4 poles

E = 480 V

Frequency, f = 50 Hz

Slip, s = 4%

A.

Speed, Vs = 120 x Frequency (Hz)/number of poles

= 120 × 50/4

= 1500 rpm

B.

Actual motor speed, V = Vs × (1 - s)

V = 1500 × (1 - 0.04)

= 1440 rpm

C.

Slip speed, s = Vs - V

= 1500 - 1440

= 60 rpm

kkurt [141]3 years ago

4 0

Answer:

a) $n_{s} = 750\,rpm$ , b) $n_{r} = 720\,rpm$ , c) $n_{p} = 30\,rpm$

Explanation:

a) Synchronous speed is:

$n_{s} = f\cdot \frac{60}{n_{poles}}$

$n_{s} = (50\,hz)\cdot \left(\frac{60}{4}\right)$

$n_{s} = 750\,rpm$

b) Actual motor speed is:

$S = \frac{n_{s}-n_{r}}{n_{s}} \times 100\%$

$n_{r} = \left(1-\frac{S}{100}\right)\cdot n_{s}$

$n_{r} = \left( 1 - \frac{4}{100} \right)\cdot 750\,rpm$

$n_{r} = 720\,rpm$

c) Slip speed is:

$n_{p} = n_{s} - n_{r}$

$n_{p} = 750\,rpm - 720\,rpm$

$n_{p} = 30\,rpm$

You might be interested in

Disconnecting means shall be capable of being locked in the open position. The provisions for locking do not have to reamin in p

Lorico [155]

The answer is a.true

7 0

3 years ago

A commuter train traveling at 50 mi/h is 3 mi from a station. The train then decelerates so that its speed is 15 mi/h when it is

jonny [76]

Answer:

a) $t = 277.477\,s\,(4.625\min)$ , b) $v_{f} = 0\,\frac{mi}{h}$ , c) $a = -0.128\,\frac{ft}{s^{2}}$

Explanation:

a) The deceleration experimented by the commuter train in the first 2.5 miles is:

$a=\frac{[(15\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,mi} )\cdot (\frac{1\,h}{3600\,s} )]^{2}-[(50\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,mi} )\cdot (\frac{1\,h}{3600\,s} )]^{2}}{2\cdot (2.5\,mi)\cdot (\frac{5280\,ft}{1\,mi} )}$

$a = -0.185\,\frac{ft}{s^{2}}$

The time required to travel is:

$t = \frac{(15\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,fi} )\cdot(\frac{1\,h}{3600\,s} )-(50\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,fi} )\cdot(\frac{1\,h}{3600\,s} )}{-0.185\,\frac{ft}{s^{2}} }$

$t = 277.477\,s\,(4.625\min)$

b) The commuter train must stop when it reaches the station to receive passengers. Hence, speed of train must be $v_{f} = 0\,\frac{mi}{h}$ .

c) The final constant deceleration is:

$a = \frac{(0\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,mi} )\cdot(\frac{1\,h}{3600\,s} )-(15\,\frac{mi}{h} )\cdot (\frac{5280\,ft}{1\,mi} )\cdot(\frac{1\,h}{3600\,s} )}{(2.875\,min)\cdot (\frac{60\,s}{1\,min} )}$

$a = -0.128\,\frac{ft}{s^{2}}$

7 0

3 years ago

5. A typical paper clip weighs 0.59 g and consists of BCC iron. Calculate (a) the number of

marta [7]

Answer:

(a) $3.185*10^{21} cells$

(b) $6.37*10^{21} atoms$

Explanation:

(a)

Volume, V of unit cell

$V=(2.866*10^{-8})^{3}=2.354*10^{-23}$

Number of unit cells, N

$N=\frac {W_{mat}}{V\rho_{mat}}$ Where $W_{mat}$ is weight of material and $\rho_{mat}$ is density of material

$N=\frac{0.59}{7.87*(2.354*10^{-23}}=3.185*10^{21} cells$

(b)

Number of atoms in paper clip

This is a product of number of unit cells and number of atoms per cell

Since iron has 2 atoms per cell

Number of atoms of iron= $3.185*10^{21} cells*2 atoms/cell=6.37*10^{21} atoms$

8 0

3 years ago

The input and output signals of a system is related by the following equation: fraction numerator d squared y over denominator d

Colt1911 [192]

Answer:

Explanation:

The given equation is :

$\frac{d^{2}y }{dx^{2} } + sin(3y) \frac{dy}{dt} + y = t\frac{df}{dt} + f$

5 0

3 years ago

The entire system of components that produces power and transmits it to the road is called the vehicle's _____.

IrinaK [193]

Answer:

Powertrain

Explanation:

6 0

3 years ago