380V angle connected electric heating tube, a total of 72kw. Motor a total of 17kw. How many currents? How thick copper wire?

380V angle connected electric heating tube, a total of 72kw. Motor a total of 17kw. How many currents? How thick copper wire?

The total power is 89kw, because the power factor of the electric heating tube is equal to 1, and the power factor of the motor is about 0.8, so the power factor is 0.95. The current = 89 / 0.38 / 1.732 / 0.95 = 142a. Theoretically, copper core wire with more than 50 square meters or aluminum wire with more than 70 square meters can be used. It is recommended to use copper wire with 70 square meters or aluminum wire with 95 square meters, which is much safer
As for resistance, the correct one in the following statement is ()
A. The resistance of copper conductor is smaller than that of iron conductor. B. the greater the resistance of conductor, the more heat generated by current passing through conductor. C. in the teaching building of a school, the more light-emitting lamps at the same time, the smaller the total resistance of circuit. D. the greater the voltage at both ends of conductor, the greater the resistance of conductor
A. In addition to the material, the resistance is also related to the length and cross-sectional area of the conductor, so a is wrong; B. according to Joule's Law: q = i2rt, the heat generated is not only related to the resistance, but also related to the size and time of the current; so B is wrong; C. in the parallel circuit, the more resistance in parallel, the smaller the total resistance; so C is correct; D. resistance is the property of the conductor, only related to the material of the conductor Material, cross-sectional area and length, and the size of the current and voltage has nothing to do with; so D error, so choose C
When a "220 V 100 W" bulb is connected to a 110 V circuit, if the influence of temperature on the resistance is considered, its actual power is 25 W
ask
Urgent~~
P=UI=U*(U/R)=(U^2)/R
When R is constant, electric power P is proportional to the second power of voltage U
Po=](Uo)^2]/R
P=(U^2)/R
P/Po=(U/Uo)^2=(110/220)^2=1/4
P=Po/4=200/4=25W
Power (=) 25W
34 kW heater, how to calculate 220 voltage and current? How many square copper wires?
Is it your 34 kW heater again?
1kW is about 4.5a, current 34Kw = 153a, current 1m2 can pass 8a, use 25m2 copper wire
You can see for yourself whether it is enough, plus the electricity consumption of other electrical appliances in your home,
The small resistance of copper wire can be reduced
In some electrical equipment, copper wire is often used instead of aluminum wire because of the resistance of copper wire under the same conditions_______ (fill in "larger" or "smaller") to reduce the_______ The loss of energy
Smaller, can reduce the energy loss caused by the current through the wire!
less
heat energy
Connect a bulb marked "220 V, 100 W" to the 110 V power supply. (1) what is the resistance of the bulb? (2) What is the actual power consumption of the bulb?
(1) According to P = u2r, the resistance of the bulb: r = u2p = (220V) 2100W = 484 Ω; (2) the actual power consumption of the bulb connected to the 110V circuit: P = u, 2R = (110V) 2484 Ω = 25W. Answer: (1) the resistance of the bulb is 484 Ω; (2) the actual power consumption of the bulb is 25W
How much current can a copper wire with a cross-section of 1 square millimeter carry? And how much current can a copper wire with a diameter of 1 square millimeter carry? Do you have a calculation formula for both?
The copper wire is 6a and the aluminum wire is 4a. The wire diameter of 1mm is less than one square, so the current carrying capacity is about 5A
The cross-sectional area of a is 0.5cm2, the cross-sectional area of B is 3mm2, and the resistance of a is smaller than that of B______ Conductor. When several conductors are in series, the total resistance is higher than that of any one conductor______ Because the series connection of conductors is equivalent to increasing the resistance of conductors______ .
(1) It is known from the title that the material and length of two conductors A and B are equal, and the cross-sectional area of a is greater than that of B, so the resistance of a is less than that of B; (2) several conductors in series increase the length of conductor, and the resistance of conductor increases, so when several resistors are in series, the total resistance is greater than any one
The power is supplied to a lamp marked "PZ & nbsp; 220V & nbsp; 100W" in a distant construction site by a power supply with a voltage of 220V. Due to the long distance, the resistance of the wire can not be ignored, and the actual electric power consumed by the bulb is 96w. Then the electric power consumed by the wire ()
A. Less than 4wb. Equal to 4wc. Greater than 4WD. 0
If the wire resistance is ignored, that is, the voltage of 220 V is all connected to the bulb of "PZ 220-100", the bulb will light normally, and the power is rated at 100 W; if the wire resistance is not ignored, that is, the resistance in the circuit will increase, and from P = u2r, the total power consumed by the circuit will decrease, that is, less than 100 W, while the actual power of the bulb is 96 W, so the power on the wire can only be less than 4 W; therefore, select a
How many amperes can 2.5 square copper wire pass
This friend, for the 2.5 square millimeter plastic insulated copper conductor, the maximum current carrying capacity of the conductor is as follows when the surrounding temperature is 25 ℃
1. Single 28a
2. Two 23a
3. Three 18a
4. Four 18a