Electrodynamical wattmeter has 4 connections, 2 for current and 2 for voltage. Why do we have both, how that works inside? Those 2 drive in current and those 2 voltage so it calculates how much power is it in there in some sort of mechanism?
What about in varmeter, why we connect one inductor...
I know that electro dynamical instrument has moving coil and stationary coil, and moving coil moves around it, does stationary coil make homogenic magnetic field? And moving coil moves around axis, and we have coil springs where they are placed and what they do? In instrument with moving coil we...
In DC circuit currents can be added if they meet at some point, but in AC current in resistor, inductor and capacitor differs, becase they are out of phase, can they be added?
Homework Statement
I have some questions about powers in AC circuit. What is the maximum and minimum current power on resistor and inductance.
Homework Equations
Um = U / V2
Im = I / V2
The Attempt at a Solution
prmax = U*I=(Um/V2)*(Im/V2)=(Um*Im)/2. But answer seems to actually be that...
Homework Statement
Two serially connected impedances one with \Phi = π/3 and other with \Phi = 0. They have apparent power of S1=S2=200VA. Find total apparent power.
Homework Equations
S = sqrt(P^2 + Q^2)
The Attempt at a Solution
so cosPhi = P1/S1. So P1=cosπ/3*200=100W...
Homework Statement
Complex current of I = (1+j) on frequency of 50 Hz. Find maximum current Im, effective current Ief, and current at time 1s, i(1)
Homework Equations
ω=2πf
i(t)=Im*sin(ωt+ψ)A
The Attempt at a Solution
Effective current is length of that hypotenuse on complex...
Homework Statement
If period of simple harmonic graph of electric current goes down by 20%, how will change the angular frequency?
Will it increase by 25π%? 25%? 50%?...
Homework Equations
T = 2π/ω
The Attempt at a Solution
So by going down by 20%, so 100%-20%, I have...
So I'm trying to solve this kind of problem And I got stuck. Capacitor with power 2000*e^(-jPi/2) and connected to voltage u(t)=282,84sin(314*t+Pi/4). Determine the capacity. I know power is P=U*I, capacitance is C = 1 / Xc*w, from that u(t) we have that w is 314, so rearraning equation P =...