Ask, the resistance/phase of the load

  • Thread starter cupcake
  • Start date
  • Tags
    Load
In summary, the problem involves calculating the resistance/phase of a balanced 3-phase purely resistive load using two different methods. The equations used are W1 = VL IL cos(30-theta) and W2 = VL IL cos(30+theta), where VL = 110, IL = 0.86, W1 = 77, and W2 = 76.5. The solution involves finding theta using the formula theta = tan-1(sqrt{3} * (W1-W2)/(W1+W2)), which results in a theta value of 0.810 and a power factor of 0.999. The final step is to calculate the resistance using the formula R = V/I, which gives
  • #1
cupcake
76
0

Homework Statement



I was asked to calculate the value of the resistance/phase of the load in balanced 3-phase purely resistive load. it stated that there are two different ways to obtain the solution.

Homework Equations



W1 = VL IL cos (30-theta)
W2 = VL IL cos (30+theta)

where Voltage Line = 110, Line current = 0.86, W1=77 and W2=76.5

The Attempt at a Solution



W1+W2=153.5

theta=tan-1 ([tex]\sqrt{3}[/tex] * (W1-W2)/(W1+W2))

thus, I obtained theta = 0.810 where cos theta (pf) = 0.999

from this, how I calculated the resistance? is it only R=V/I = 110/0.86 = 127.91? or using the wattmeter result?
 
Physics news on Phys.org
  • #2
help..anyone?
 
  • #3
There are a few things I don't understand about your question... But, I will be direct, first.

You know that R = V/I. Also, you have figured out what the resistance is and what the phase is. So what's your problem?
 

FAQ: Ask, the resistance/phase of the load

What is the difference between resistance and phase of a load?

Resistance refers to the opposition that a material or device presents to the flow of electrical current. It is measured in ohms and can be thought of as the "friction" that hinders the flow of electricity. Phase, on the other hand, refers to the timing relationship between two oscillating signals. In the context of a load, phase refers to the timing difference between the voltage and current in an alternating current (AC) circuit.

How do you calculate the resistance of a load?

The resistance of a load can be calculated using Ohm's Law, which states that resistance (R) equals voltage (V) divided by current (I). In other words, R = V/I. The unit of resistance is ohms (Ω).

Why is the resistance of a load important?

The resistance of a load is important because it determines the amount of current that can flow through a circuit. Too much resistance can cause a circuit to overheat or malfunction, while too little resistance can cause a circuit to draw too much current and potentially damage components.

What factors affect the resistance of a load?

The resistance of a load can be affected by several factors, including the material of the conductor, the length and thickness of the conductor, and the temperature of the conductor. Generally, materials with higher conductivity, shorter and thicker conductors, and lower temperatures will have lower resistance.

How does the phase of a load impact electrical circuits?

The phase of a load can impact electrical circuits in several ways. If the phase difference between voltage and current is not aligned, it can cause power losses and inefficiencies in the circuit. In industrial applications, maintaining proper phase relationships is important for efficient power transmission and distribution. In addition, phase shifting devices can be used to change the phase of a load for specific applications, such as in AC motors.

Similar threads

Three phase AC concepts and problems
Replies
2
Views
5K
Delta-Delta 3 phase transformer HNC help
Replies
8
Views
2K
Why did they use only meter resistance for tau of inductor
Replies
4
Views
1K
Determine the load voltage levels in feeder systems
Replies
15
Views
2K
Engineering Total power factor, 1 motor, three phase, two loads
Replies
1
Views
3K
Load resistance, dissipated power, transformers. (AC)
Replies
5
Views
3K
Balanced Y-connected 3-phase load
Replies
3
Views
2K
Answer:Iph=7A, IL=12.12A, P=65.65W, Q=1538.6VAR, Theta=87.55ْ
Replies
2
Views
1K
Calculating Symmetric Components in a Three Phase 4 Wire System
Replies
23
Views
5K
Engineering Line Current for 30kW 3 phase motor
Replies
2
Views
13K

Hot Threads

Recent Insights

Back
Top