![](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>)
Characteristics of series circuit voltage expression characteristics of parallel circuit voltage expression——
The sum of the voltages of each part of the series circuit = the total voltage
U＝U1＋U2＋U．．．
Voltage on each branch of parallel circuit = total voltage
U=U1=U2=U...
Is the total voltage of the series circuit equal to the supply voltage?
Is the voltage of each branch equal to the supply voltage?
No
Series u total = U1 + U2 + U3 +... + UN
Series connection, not to mention branch connection
Parallel is the only way!
In parallel, u = U1 = U2 = U3 =. = UN
Why is the total voltage at both ends of the series circuit equal to the sum of the voltages at both ends of each part of the series circuit?
There are some in this book. Because there is only one line in series, the current is equal everywhere. The voltage is equal to the current multiplied by the resistance, and the total voltage is equal to the total resistance multiplied by the current. The total resistance is added up, so the total voltage is also added up
The law of voltage and current in series and parallel circuits
The voltage sum of each part of the series circuit is the supply voltage and the current is equal everywhere
The voltage of each branch in parallel circuit is equal, and the sum of each branch current is equal to the main current
RELATED INFORMATIONS
- 1. Characteristics of series and parallel current and voltage
- 2. The law of voltage in series circuit and parallel circuit,
- 3. What is the law of series circuit voltage?
- 4. Check the home circuit. Install the bulb with rated voltage of 220 V to the position of the circuit breaker and remove the circuit breaker. After the switch is closed, the bulb will light normally It can be judged that the a circuit is completely correct There is a short circuit in circuit B Open circuit in C circuit D can't judge if there's a problem Analyze again. Be careful. Good score. Choose d first
- 5. A fan with a resistance of 4 ohm, working voltage of 220 V, measured working current of 5 A, calculated fan input power, fan thermal power, electric energy conversion machine Energy power
- 6. What is the function of the fuse on the knife switch? 0 - 14 days and 23 hours to the end of the problem A netizen said [knife switch can't protect household appliances at all. General household appliances have their own protection functions (such as over-voltage protection, over-current protection and under voltage protection). As long as they are operated normally, household appliances generally won't break down. The failure of household appliances is generally caused by their own quality problems, aging internal components, wrong operation of users and lightning] If according to this netizen's opinion, I match the fuse tube to the knife switch, its size and thickness? I don't know if this netizen's opinion is reasonable?
- 7. Current, voltage, resistance. Relationship with power /? Current, voltage, resistance. Relationship with power/
- 8. For example, some fans need 12V voltage, but the current is only 0.5A, the power is 6W, some fans only need 5V, but the current is 1.2A Now the question is how to control the voltage and current. Another is how to change the 220 V AC into 5 V output without heating Add 100 points after explanation And then there is the adjustment of the fan gear. It should not use the rheostat to divide the voltage. Is it to directly lower the voltage to make the current smaller? The power smaller? Is it slow? I mean, how do I do it for a fan? The same power can have different voltages and currents. Of course, I hope that the voltage is high and the current is low. Can I make a 220 V voltage with 0.01 a current How does the AC / DC module work
- 9. Is kinetic energy converted into electricity? How is kinetic energy transformed into electrical energy? What is the relationship between them? How is electrical energy transformed into kinetic energy?
- 10. How does the energy consumption braking of motor change the stored mechanical energy into electrical energy
- 11. Why is the voltage at both ends of each branch equal to the supply voltage in parallel circuit?
- 12. The internal resistance of an electric fan is 20 Ω. After connecting with the voltage of 220 V, the electric power consumed during normal operation is 66 W (1) What is the current passing through the electric fan motor during normal operation? (2) what is the power converted into mechanical energy and internal energy when the electric fan is working? What is the efficiency of the motor at this time? (3) if the electric fan blade is stuck and cannot rotate after the power is connected, how much is the current passing through the motor? How much is the electric power and heating power consumed by the motor?
- 13. Is 380V AC contactor coil 380V?
- 14. The power frequency AC voltage of 220 V and 380 V in engineering refers to its maximum value (a), instantaneous value (b), average value (c) and effective value (d)
- 15. University electrician! Under the condition of constant power supply voltage, if the triangle connection of the motor is wrongly connected into a star connection, or vice versa, what are the consequences?
- 16. The purpose of star delta Depressurization So the line current is a fixed value. The star phase current is equal to the line current, which is the value. The △ phase current is one third of this value. So the △ phase current is smaller
- 17. How many times of the line current of squirrel cage three-phase asynchronous motor when it is star connected is that when it is triangle connected?
- 18. The three voltages of one equipment are 380V, the load current of the main switch is 160A, the rated capacity of the equipment is 65kva, and the power factor is about 0.95 The three voltage of a device is 380V, the main switch of load current is 160A, the rated capacity of the device is 65kva, and the power factor is about 0.95, Can this 160A be used as the total current?
- 19. There is a small bulb of ammeter and voltmeter in series circuit Among them, the voltmeter measures the normal light of the small bulb The position of ammeter bulb is changed Write down what's going to happen next
- 20. Xiaohong and Xiaowei have done the experiment of "measuring the electric power of small light bulb". There are two kinds of power supply (voltage is 6V), voltmeter, ammeter and sliding rheostat (a is marked with "50 Ω & nbsp; & nbsp; 2A", B is marked with "20 Ω & nbsp; & nbsp; It is known that the rated voltage of the two small lamps are 2.5 V and 3.5 V respectively, and the rated current is the same. They choose the equipment to carry out the experiment. Xiaohong connects the circuit correctly, connects a small lamp into the circuit, closes the key, moves the slide of the rheostat, and observes that the small lamp lights normally when the slide is near the midpoint. The ammeter shows the following As shown in the figure. ① during the experiment, the rheostat selected by Xiao Hong is______ (choose "a" or "B"), the rated voltage of the lamp she measured is______ V, rated current of______ Please calculate the rated power of Xiaohong and Xiaowei according to the relevant information______ (write the calculation process)