Circuit current calculation! Excuse me? Three heating tubes: 2kW, triangle connection in three-phase circuit, how to calculate line current? Three lamps: 2kW, star connected in three-phase four wire circuit, how to calculate the line current? I said the load is 2kW respectively, which means there are three loads connected in the circuit according to the star and triangle line! Is 2kW ／ 6kW ／ or what method should be used to calculate the resistance separately? Is the total resistance the same when the connection method is not used?

Triangle connection (rated voltage of heating tube 380V)
I = P ﹣ u ﹣ 3 (3 square root) = 2kW * 3 ﹣ 380 ﹣ 3 = 6000W ﹣ 380V ﹣ 1.732 = 9.12a
Star connection (rated voltage of lamp tube is 220 V)
I=P÷U=2kW÷220V=2000W÷220V=9.09A
In addition, because the "star connection method is connected in three-phase four wire circuit", each load can only be calculated separately according to 220 V, and each load has the same power, so only one can be calculated. That is: A, B, C three-phase current is equal (9.09 a)

Why does this circuit calculate current in this way?
In the series circuit, there are two power supplies E1 and E2, and three resistors R1, R2 and R3. The current direction is the same as that of E1
Seeking current
Why I = E1-E2 / R1 + R2 + R3
Why use E1-E2?

Potential difference

How to calculate the electrothermal conversion efficiency in junior high school physics?
Rt

If it only produces heat, then it is 100%. If it also produces other energy, then the total electric energy consumed is UI, and the heat generated is I ^ 2rt. The latter is the conversion rate in addition to the former

A number consists of 3 10, 9 1, 5 0.1 and 4 0.001
This number is written as (), and this number is read as (); keep it to two decimal places, about (), and keep the whole number, about ()

The number is 39.504 in writing and 39.504 in reading
Keep two decimal places: 39.50
The reserved integer is about 40

On a map with a scale of 1:2000000, the distance between a and B is 8 cm. How many kilometers is the actual distance between a and B?

A: the actual distance between a and B is 160 km

In the quadrilateral ABCD, AB is parallel to CD, and the lengths of AB and CD are two roots of the equation x & sup2; - 2mx + (m-1 / 2) & sup2; + 7 / 4 = 0 of X, if M and N are
One dollar twice question... Wanted responder
In quadrilateral ABCD. AB is parallel to CD, and the lengths of AB and CD are the two roots of the equation x & sup2; - 2mx + (m-1 / 2) & sup2; + 7 / 4 = 0 of X. if M and N are the midpoint of AD and BC respectively, and Mn = 2, what is the value of M

Let two roots of the equation be a and B, so a + B = 2m
Mn is a trapezoidal median line
Mn = 2, so AB + CD = 2Mn = 4
So a + B = 4
So 2m = 4
So m = 2
Substituting into the equation, we get x ^ 2-4x + 4 = 0
A = 2, B = 2, the equation has solution
So m = 2

A, B, C three piles of coal, a pile of coal weight is 2 / 5 of the weight of B, C, B pile of coal weight is 1 / 4 of the weight of a, C pile of coal weight 360 tons, a, B each weight?
Ask for formula, and those who don't have formula don't

Suppose: the coal weight of pile a is x tons
[(x+360)*1/4+360]*2/5=x
The answer is your own

Solve the inequality about X; x-ax + A-1 > 0, a is a real number

X-ax + A-1 > 0, (x + 1) (x-1) - A (x-1) > 0, (x-1) (x + 1-A) > 0

After three hours, car a meets car B at the midpoint of 18 kilometers. At this time, the distance ratio of car a to car B is 2:3. How many kilometers do car a and car B travel per hour?

2 + 3 = 5, 18 × 2 ／ (35-25), = 36 ／ 15, = 180 (km); car a: 180 ／ 5 × 2 ／ 3 = 24 (km); car B: 180 ／ 5 × 3 ／ 3 = 36 (km); answer: car a travels 24 km per hour, car B travels 36 km per hour

The solution set of inequality | x ^ 2-4x + 3 | is

x²－4x＋3＞0
(x－1)(x－3)＞0
X < 1 or x > 3

Why does this circuit calculate current in this way? In the series circuit, there are two power supplies E1 and E2, and three resistors R1, R2 and R3. The current direction is the same as that of E1 Seeking current Why I = E1-E2 / R1 + R2 + R3 Why use E1-E2?

How to calculate the electrothermal conversion efficiency in junior high school physics? Rt

A number consists of 3 10, 9 1, 5 0.1 and 4 0.001 This number is written as (), and this number is read as (); keep it to two decimal places, about (), and keep the whole number, about ()