![](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>)
There is a "220v40w" light bulb A. how many can a "220v5a" electric energy meter connect to this kind of light?
According to the formula P = UI, it can be calculated that the current of bulb a is about 0.18a. About 27 bulbs can be connected. Ask: if connected to 110V power supply, how much is the actual power? Answer: don't discuss whether the actual light is on or not. Suppose that the rated current of this bulb is about 0.18a, and the power is about 20W when connected to 110V power supply!
What is the maximum allowable power of the meter marked "220v5a"? How many "220v60w" bulbs can be connected at the same time?
In direct current, P (power) = UI = 220V * 5A = 1100W, divided by 60W = 18.33, so up to 18 220v60w bulbs can be connected
As shown in the figure, there are two lighting bulbs of different specifications. A lamp is marked with "220 V, 40 W", B lamp is marked with "220 V, 25 W", now they are connected in parallel with the voltage stabilizing circuit of 220 v. then the following statement is correct: (1) B lamp must be darker than a lamp; ② At the same working time, lamp a must consume more power than lamp B. ③ the actual power of the two lamps may be the same, so they may be on the same light. ④ only from the information in the title, it is impossible to judge which lamp is brighter
A. ①②B. ②③C. ②③④D. ②④
∵ when the energy-saving lamp works, most of the electric energy is converted into light energy, and the incandescent bulb converts most of the electric energy into internal energy, and a small part into light energy, ∵ the luminous efficiency of the energy-saving lamp is greater than that of the incandescent lamp, ∵ the voltage at both ends of each branch in the parallel circuit is equal, and the bulb lights normally under the rated voltage, ∵ A and B are connected in parallel at 22
The specification of a lighting bulb is "220 V & nbsp; & nbsp; 40 W". If 110 V voltage is applied at both ends of the bulb, the actual power of the bulb is ()
A. 10WB. 20WC. 30WD. 40W
It is known that the rated voltage of the bulb is 220 V, the rated power is 40 W, the resistance value of the bulb: & nbsp; r = U2, P = (220 V) 240 w = 1210 Ω; the actual power of the bulb: P = U2, actual r = (110 V) 21210 Ω = 10 W
RELATED INFORMATIONS
- 1. What will happen if a small light bulb (2.5V 0.3A) and a household incandescent lamp (220V 40W) are connected in series to a 220V power supply? There are four options. What do you choose? A small light bulb and incandescent light bulb are on B small bulbs and incandescent lamps are burned out C small bulb short circuit, incandescent lamp normal light D small bulb burned out, incandescent lamp in good condition, but does not emit light Please talk about your ideas
- 2. What do the numbers in 3 * 4 * 1.5 (6) mean?
- 3. The meaning of 3 × 10 (40) a meter 1、 What do you mean by "3", "10" and "40" in the 3 × 10 (40) a meter? 2、 On the premise of safety, what is the maximum allowable power?
- 4. What does 10 (20) a mean on an energy meter?
- 5. The electricity meter of a classmate's home is marked with 220V, 10a and 3000r/ The electric energy meter is marked with "220V 10A" and "3000r / kWh", which indicates that the electric energy meter can be connected to the electric appliances with a total power of () W at most. One day, all the electric appliances in the student's home (with a total power of 600W) work for 4h, then the dial of the electric energy meter will rotate ()? The second question needs process. The first question is I will, train of thought or process,
- 6. A household electric energy meter has 3000r / kWh on it. If the meter is used to measure the power of the terminal electric appliance, the turntable turns 15 times in 3 minutes The work done by the current_____ Kilowatt hour=_____ Coke, what's the power of this consumer____ tile
- 7. A watt hour meter is marked with 3000 R / kW · h. now it is observed that the watt hour meter rotates 45 times in 10 min. how much work does the current do?
- 8. 2. The surface of an electric energy meter is marked with 3000r / kWh. If there are several 100W electric lamps in this circuit, observe the turntable and measure that the turntable has turned 50 revolutions in 5 minutes. If the switch is not opened or closed during this period, it will turn 50 revolutions in this period______ Two lights are used at the same time Is there an analysis process
- 9. The dial of a household electric energy meter is marked with the word "3000r / kW · H". If an electric water heater is used alone, the dial turns 210 revolutions in 300s, The energy consumed by the water heater, And how much heat the water heater can give off to make the water temperature reach 10 ℃
- 10. The watt hour meter is marked with "3000r / kWh". If only one consumer works in the circuit of the meter, the dial of the watt hour meter will turn 30R in 6 minutes Then, the electric energy consumed by the appliance is ［ J, and the current passing through it is ］ a
- 11. If the dial of the electric energy meter is marked with the words of 220V and 5A, the total power of the electric appliance that the electric energy meter can connect cannot exceed () kW
- 12. An electric energy meter is installed on the home circuit. The turntable turns 180 turns in 2 hours An electric energy meter is installed on the home circuit (trunk road). The turntable of electric energy is measured to rotate 180 times within 2 hours. How many joules of electric energy are consumed by the appliance during this period? (the electric energy meter is marked with 600 revs / kW. H) Answer clearly
- 13. A watt hour meter is marked with the word 3000kW. H. now it is observed that the watt hour meter rotates 45 times in 10 minutes. How much work has the current done?
- 14. There is 3000r / kW. H on the dial of an electric energy meter. Use the electric energy meter and stopwatch to calculate the electric power of an electric lamp and let the lamp work independently, It takes three minutes to find out: (1) what is the electric energy consumed by the lamp? (2) the electric power of the lamp
- 15. The words "2500r / kWh" are marked on the household electric energy meter. If an indoor electric appliance works alone for 30 minutes and the turntable rotates for 50 turns, the consumption of the electric appliance is less than 50% If the power of the appliance is Watt, the working hour of the appliance consumes 1 kwh I hope brothers and sisters can give the calculation process
- 16. Energy meters are used to measure energy______ A meter marked with "220V & nbsp; 5A" can be used for the meter with maximum power of 0______ Watt on the lighting circuit
- 17. What is the principle of the test button on the leakage protector
- 18. A copper wire with a cross-sectional area of 100 square millimeter weighs more than 1 meter The specific gravity of copper is 8.92 g / cm3. How heavy should a meter of wire be? Summer solstice is coming, man, I'm the same as you, but I'm wrong. What's the matter? The actual weight is much more than the theoretical weight
- 19. The conductor is a. glass plate B. rubber rod C. plastic rod D. copper wire
- 20. How to calculate the weight of 240 copper wire