Answer / pavan

Mechanical degrees: the degree of physical or mechanical
rotation a single conductor in an alternator.

Electrical degrees: the degree or the cycle of emf induced
in a single conductor in an alternator

Consider a Two pole Alternator, when a conductor rotates in
the feild, the emf induced in the conductor will be maximum
when the conductor is at the center of the pole and the emf
induced will be minimum when the conductor is in the middle
of the gap between the two poles. so when we consider the
graph of the induced emf versus the position or degree of
rotation. For one complete rotation of the condutor in the
feild - One complete cycle of emf is generated in the
conductor (Positive half cycle at south pole and negative
halfcycle at north pole).

The same way when we consider a 4 pole alternator a single
conductor when completing one mechanical rotation will
cross the four poles there by giving the induced emf graph
with two positive half cycles and two negative halfcycles
which gives us two complete cycles of induced emf.

So for One Mechanical rotation (360 degrees) the induced
emf completes two cycles (360 * 2 = 720 degrees in terms of
the sine wave)

So the relation between Electrical and Mechanical degrees
can be written as

Elect. Degrees = (N0. of Poles / 2) * Mech. Degrees

Source: Elecrical Machinary by P.S.Bimbhra

Answer / sunny singh

electrical angle is angle of out sin wave (emf) genrated by
rotor in corrosponding to actual rotation. In two pole
configuration conductor comes under north pole for every 90
degree rotation .so for 360 degree output sin wave cover
360 means one complete cycle but in 4 pole configuration
for 360 degree actual rotation produce 2 cycle of sin wave
so here electrical dgree is double of mechanical dgree .

electrical dgree= p/2 mechanical degree

Answer / bijay kumar sutar

1deg mech =( p/2)×electrical deg

Show formula which gives full load current 4.8 amps of a 3 HP motor and 27 amps of a 20 HP motor having 3 phase 460 volts, 0.8 Pf.

2 Answers  

---

Sir,I have finished my B.E in the Stream of EEE.How Can I get C license for Electrical???Please Tell me the way...My mail ID is praba1003105@gmail.com Cell:7402474123

1 Answers  

---

ALONG WITH MEGGER TEST FOR CHECKING OF MOTOR ,WHY WE MEASURE FOR RESISTANCE AND INDUCTANCE?

4 Answers   L&T,

---

hi i m going to attend bhel interview on 22nd sep 2008 for ET(electrical engineering).pls guide me how to prepare for the interview.i am a fresher.

1 Answers   Bhel,

---

flush point of transformer?

2 Answers  

---

What is time response of the control system?

0 Answers  

---

what you mean by current? what you mean by voltage? what is difference between star and delta connection in motor side?

2 Answers   Adani,

---

Difference between Earthing Truck & Earthing trolly for HT panel

0 Answers   Moolchand Medcity,

---

solar cell voltage?

2 Answers  

---

What is the formula to calculate the size of Aluminium and copper cable?

0 Answers  

---

when a motor is connected in parallel with the existing motor the pf will change or not?

9 Answers  

---

what is divercity factor?

4 Answers   ABB,

---