№2 – pracrical work

2.3-exercise. The frequency of the electrical circuit (Figure 2) with R=4 Om, L=6.37 mG, S=159 mkF is provided by the F=200 Gs and the voltage U=120 V li sinusoidal current generator. Let the phase shift between the current in the chains, the current in the chain parts, and the voltage and power of the raw parts, as well as the active, reactive and full power of the chain be considered.
To solve:


R, L and S electrical circuit in which elements are connected in series

Calculation of resistances and phase shifts. The chain seen has both types of reactive resistances, along with active resistance. These are:

Inductive
Х   L
 1256
 6 .37
 10
^{ 3  8} Om.

L
  2f
 2  3,14
1
 200
 1256 Гц

capacity
Х 

с
  С

1256


 159
 5
 10 ^{ 6}
Om.

Reactive resistance of the chain ^Х

Full chain resistance ^{Z }

 X _L  X _C
 8  5  3



Om.
^{ 5} Om.

Phase shift
cos   ^R
Z
4
  0 .8
5
or


U
tg   ^X
R
120
3
  0 .75
4
  37 ⁰

Calculation of the current strength given to the chain. ^{I  }
Z

Voltage drops in parts

 24 _A.
5

R
U  R  I
 4  24
 96
V.,

L
U  X _L  I

C
U  X _C  I
 8  24
 5  24
^{ 192} V.
^{ 120} V.

Calculation of the power of the chain.

Active power ^P
 UI
cos 
 R  I ²
 4  24 ²
 2304
vt.

Reactive power Q
 UI
sin 
 X  I ²
 3  24 ²
 1728
var.

Full power of the chain .
S  UI 
 Z  I ²
 5  24 ²
 2880
VA.

Construction of a chain vector diagram.
I
Check ^{U    120} V.

Issues for independent solution:

1-exercise. Inductance L = 1.6 G and asset resistance R=400 Om. Is the reel voltage U=280 V, the frequency F=40 Gs li is supplied from the alternating current source. Let the current, power coeficent, asset, jet and full power triangle in the chain be built.
2-exercise. To determine the AC resistance R and inductance L of the reel, its voltage is connected to the alternating current network U=220 V, and the current in the reel is I=3.67 A. power p = 485 W was measured. If f=50 Gs, let R and L be considered.
^{3-exercise. A parallel chain with resistances R= XL=XC=20 Om is connected to an alternating current network with a voltage U=220 V. Let the currents passing through the resistances, the total current and the covvat coefficient of the chain be determined.}


Control questions:

1. 
   Tell us about the AC source?
   
2. 
   Distinguish between active and reactive resistances?
   
3. 
   Explain the difference between inductive and capacitive resistances?
   
4. 
   Explain the alternating current chain to which consumers are connected in series?
   
5. 
   Explain the alternating current chain to which consumers are connected in parallel?
   
6. 
   What do you mean by a triangle of forces?