In order to write a good problem statement, you need to identify the following components of the problem.

Re armature of a 4 pole DC generator is required to generate an emf of 520v on open circuit when revolving at a speed of 660rpm.

bija089 [108]

Since the armature is wave wound, the magnetic flux per pole is 0.0274 Weber.

Given the following data:

Emf = 520 Volts

Speed = 660 r.p.m

Number of armature conductors = 144 slots

Number of poles = 4 poles

Number of parallel paths = 2

To find the magnetic flux per pole:

Mathematically, the emf generated by a DC generator is given by the formula;

$E = \frac{\theta ZN}{60}$ × $\frac{P}{A}$

Where:

E is the electromotive force in the DC generator.

Z is the total number of armature conductors.

N is the speed or armature rotation in r.p.m.

P is the number of poles.

A is the number of parallel paths in armature.

Ф is the magnetic flux.

First of all, we would determine the total number of armature conductors:

$Z = 144$ × $2$ × $3$

Z = 864

Substituting the given parameters into the formula, we have;

$520 = \frac{\theta (864)(660)}{60}$ × $\frac{4}{2}$

$520 = \theta (864)(11)$ × $2$

$520 = 19008 \theta \\\\\Theta = \frac{520}{19008}$

Magnetic flux = 0.0274 Weber.

Therefore, the magnetic flux per pole is 0.0274 Weber.

5 0

3 years ago

Which of the following positions would be responsible for attaching I-beams to a crane?

prohojiy [21]

Answer:

Rigger

Explanation:

work as one

4 0

3 years ago

The value of Rth is *

Vladimir79 [104]

Johnjjjjjjhhhhhhhhjjjjjjjjjjj

4 0

3 years ago

Advantage of a sheave wheel in a shaft headgear

NikAS [45]

Answer:

sorry if wrong

Explanation:

One sheave means that you are using a single drum winder. They are the worst! Double drum winders control easier, brake better and are much more efficient. They save time ( two skips or cages) and can be clutched to perform faster shift transport. A single drum is slow, unbalanced and can be a nightmare if it trips out during hoisting. If the brake system is not perfect it can be a real hairy experience. For a runaway single drum, there is no counterbalance effect. It always runs to destruction. With a double drum, the driver still has a chance to control the winder to a certain extent and he has two sets of brakes to rely on. A single sheave could also mean a shaft with a single compartment. No second means of escape unless there are ladders or stairways. Not a very healthy situation.

Those are just a few points. I am sure much more can be said in favor of a double drum winder and two or more sheaves in the headgear. Most of the shafts I have worked at have multiple winders and up to ten compartments. They all have a small single drum service winder for emergencies and moves of personnel during shift times. They are referred to as the Mary - Annes. Apparently, the name originated in the U.K. where an aristocratic mine owner named the first such winder after his mistress.

5 0

3 years ago

If two statements are inconsistent with each other, at least one of them must be false. a)-True b)-False

olchik [2.2K]

Answer:

a)- True

Explanation:

If two statements are inconsistent with each other it means that they are not telling the same, if they are not telling the same it means that only one of them COULD be true, but there is a third option where the two statements are wrong and non statement is telling the true...so:

If we have two statements inconsistent with each other, AT LEAST one of the statements is false.

7 0

3 years ago