![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
The rated power of a motor is 4.4kw, the rated voltage is 220kV, and the resistance of the power supply line is 1.8ohm How many watts of power is consumed on the circuit when the motor works normally?
In fact, this motor can't work normally. The loss power of the series connected motor with line resistance is 4.4kw, and its passing current is about:
I＝P/U/COSφ＝4.4/0.22/0.85≈23.5(A)
Voltage consumed on the line:
U＝RI＝1.8×23.5≈42(V)
Power consumed on the line:
P＝U×U/R＝42×42/1.8＝980(W)
In the circuit as shown in the figure, when the resistance of 4 Ω is connected between two points AB, the power consumed is 16W. When the resistance of 9 Ω is connected between two points AB, the power consumed is still 16W
(1) When R1 = 4 Ω is connected between two points of AB, u = I1 (RL + R0) ---- ①∵ P = I2R ∵ the current in the circuit: I1 = p1r1 = 16w4 Ω = 2A; when 9 Ω is connected between two points of AB, u = I2 (R2 + R0) ---- ②, ∵ P = I2R ∵ the current in the circuit: I2 = p1r2 = 16w9 Ω = 43A. (2) from ① and ②, I1 (RL + R0) = I2 (R2 + R0), that is: 2A × (4 Ω + R0) = 43a × (9 Ω + R0), the solution is: R0= 6 Ω, substituting into the formula: u = I1 (RL + R0) = 2A × (4 Ω + 6 Ω) = 20V A: (1) when the resistance of 4 Ω and 9 Ω is connected between ab points, the current in the circuit is 2a and 43A respectively; (2) the voltage of the power supply is 20V
L1 8V 4W L2 is not marked L2 resistor 8 ohm, after it is connected in series, the normal light-emitting a circuit voltage 8V B circuit voltage 12V C L2 power 4W dl2 2W
You mean, both lights are on
BD right
The current in lamp L1 is I = P1 / U1 = 4 / 8 = 0.5 a
Because they are connected in series and light normally, the voltage of lamp L2 is U2 = I * R2 = 0.5 * 8 = 4 V, and the power of lamp L2 is P2 = I * U2 = 0.5 * 4 = 2 W
So the circuit voltage is u = U1 + U2 = 8 + 4 = 12V
RELATED INFORMATIONS
- 1. Two bulbs are connected in parallel in the circuit, the resistance of 3vl1 is 20 ohm, and the resistance of L2 is 10 ohm. Calculate the current of circuit 2 of 1 bulb L1 and L2
- 2. Use an ohmmeter to measure the resistance value of a resistance R, set the selection knob at "× 10" position, and the pointer is in the middle of the 100 and 200 scale arc lines when measuring A. R=150ΩB. R=1500ΩC. 1000Ω＜R＜1500ΩD. 1500Ω＜R＜2000Ω
- 3. How many ohms are the chip resistors 102, 12 and 5R1 The resistance is burnt. I want to change it,
- 4. Is 5wr22j a 5w22 ohm resistor? Is the resistance 5w22 ohm?
- 5. What's the resistance of 24 ~ 27 ohm 5W? How to distinguish the resistance from W?
- 6. What is the ohm of resistance 5W r015j?
- 7. In the home circuit, the filament resistance of an incandescent lamp is 484 ohm when it normally emits light In the home circuit, the filament resistance of an incandescent lamp is 484 ohm when it normally lights up. How much power is consumed by the lamp when it normally lights up for one hour? How much kwh is consumed?
- 8. How many kilowatts can 4 square copper core line bear
- 9. What is the resistance of a copper wire with a length of 1m and a cross section of 1mm
- 10. Why can't fuses be replaced by copper wire, aluminum wire or iron wire? extra urgent
- 11. There are three resistors marked with 100 ohm 4W 12.5 ohm 8W 90 ohm 100W respectively. The maximum voltage allowed to be added when they are connected in series is () v. they are allowed to be added when they are connected in parallel
- 12. When repairing an electrical appliance, you need a 4.5 ohm resistor. Now there are 2 1 ohm resistors, 4 9 ohm resistors, and 2 4 ohm resistors. What can you do
- 13. The ratio of power consumption is () A.2:1 B.1:2 C.4:1 D:1:4
- 14. There is a bulb with rated power of 100w220 V, and the resistance of the wire is 2.42 ohm. How much is the actual power of the bulb
- 15. When the voltage at both ends of a resistor is 6, its resistance is 20 ohm. When the voltage at both ends of the resistor becomes 0 V, how many ohm is its resistance? When it becomes a superconductor at ultra-low temperature, how many ohm is its resistance
- 16. Add 3V to a 1 ohm resistor, and I =? P =? If the maximum power of the resistor is 25W, how much voltage can it bear If it works in a circuit with 15V input, 5V output and 3a current, can it work?
- 17. 48v20a battery, with what power controller and motor is more appropriate? Can it be equipped with 800W motor and controller? What will be the consequences? About the battery and motor, controller collocation, the more detailed the better, I want to assemble the car, to take into account the distance and power
- 18. If an 11 watt (0.01 kW) energy-saving lamp has the same lighting effect as a 60 watt (0.06 kW) incandescent lamp, and their service life is more than 3000 hours, the price of energy-saving lamp is 30 yuan, the price of incandescent lamp is 2.5 yuan, and the electricity charge is 0.48 yuan / (kWh), when they are used for 1500 hours, how much is the cost of energy-saving lamp? How much is the cost of incandescent lamp?
- 19. Problem! An energy-saving lamp with a power of 10 watts (0.01 kW) costs 60 yuan; an incandescent lamp with a power of 60 watts (0.06 kW) costs 3 yuan, and its service life is the same. The electricity charge for more than 3000 hours is 0.5 yuan / kW / h. what kind of cost saving do consumers choose? Solution: the total cost of energy-saving lamp is Y1, and the total cost of incandescent lamp is Y2 ①Y1>Y2 Y1-Y2>0 X
- 20. Power cord classification and various power cord can use how much power of electrical appliances