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As shown in the figure, it is a schematic diagram of the electric blanket circuit. R0 is the resistance wire in the electric blanket, R is the resistance in series with the resistance wire of the electric blanket, the electric blanket is marked with "220 V & nbsp; 100 W", and S is the switch that controls the electric blanket in the heating state or the heat preservation state. (1) use the learned common formula to explain whether the electric blanket is in the heating state or the heat preservation state when the switch S is disconnected? (2) If it is required that 60 J of electric energy is converted into internal energy per minute when the current passes through the resistance wire R0 during heat preservation, what is the resistance value of the resistance R?
(1) As shown in the figure, when switch S is off, R0 is connected in series with R, P = u2r, total = u2r0 + R, when switch S is closed, R is short circuited, at this time, P = u2r, total = u2r0. Therefore, the power of closing is greater than that of opening. Therefore, more heat is generated during closing in the same time, so when switch S is off, the electric blanket is in thermal insulation state. (2) according to "220 V & nbsp; R = (U) 2p = (220V) 2100W = 484 Ω, because R0 has 60j electric energy converted into internal energy every minute. According to the formula q = i2rt, I2 = QRT = 60j484 Ω × 60s, I = 122a, so the voltage on R0 is U0 = I · r = 122a × 484 Ω = 22V, so the voltage on R is U1 = 220v-22v = 198v, so the resistance of R is r = u1i = 198v122a = 4356 Ω
The electric heater works by electricity. When an electric heater works normally, the current through the electric heater is 5a, which is generated in 1min
The electric heater works by using. When an electric heater works normally, the current passing through the electric heater is 5a, and the heat of 6.6x10 fourth power J is generated in 1min, then the electric power of the electric heater is w, its normal working voltage is V, and the resistance of the electric wire is Ω
It's better to have a process
The electric heater works by using the thermal effect of current (when the current flows through the resistance, the resistance will generate heat). If the current passing through the electric heater is 5A and the heat of 6.6x10 is generated in 1min, the electric power of the electric heater is 220 W, w = u * I * t = P * t, so p = w / T = 66000 / 300 = 220 W, and its normal working voltage is 44
An electric water heater, connected to the lighting circuit, consumes 48000 joules of electricity per minute when heating. How many amperes is its working current
The title says that it is connected to the lighting circuit, which means that the voltage U = 220 V, t = 1 min = 60 s, the power consumption per minute when heating is 48000 joules, which means that q = 48000 J. then according to the formula P = q / T = 48000 J / 60 s = 800 W, according to the formula P = UI, I = P / u = 800 w / 220 V = 3.64 a
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- 1. The electric power of an electric heater is 1500W. If the electric heater works for 20min every day, it will consume electric energy for 30 days______ Degree
- 2. Xiaoming's family has electric fans and incandescent lamps with rated power of 40W. They work normally for the same time____________ Generate heat Many. Xiaoming's family also has a "220V 1500W" electric water heater, which is separately connected in the circuit. It is found that the aluminum plate on the electric energy meter (as shown in the figure) rotates 125 revolutions in 121s, and the electric water heater consumes a lot of energy____________ J's electric energy, the actual voltage of his home is____________ 5. (the resistance value of the resistance wire in the electric water heater remains unchanged)
- 3. The word "220 V, 40 W" is marked on the white woven lamp. 220 V indicates the voltage of the light bulb, called. Voltage, 40 W. the electric power of the light bulb is called power
- 4. Bulbs L1 and L2 are marked with "22ov 25W" and "220V 15W" respectively. If the two bulbs are connected in series, the voltage ratio of the two lamps is? The ratio of the actual power consumed is?
- 5. If an electric furnace is connected to a circuit with a voltage of 220 V and the energy consumed in 10 min is 6.6 times 10 quintic J, the electric power of the electric furnace is [] The current through it is [], and the resistance of the furnace wire is
- 6. As shown in the figure is the internal circuit structure diagram of a household electric heater, in which R1 and R2 are heating resistance wires (R1 > R2). The following four connection modes of resistance wires can make the electric heater provide different heating power, in which () A. The connection mode of a has the smallest heating power, the connection mode of B. B has the smallest heating power, the connection mode of C. C has the largest heating power, and the connection mode of D. D has the largest heating power
- 7. Resistor R1 is 12 ohm. Connect it in series with R2 and connect it to 8V power supply. It is known that the voltage at both ends of R2 is 2V. Calculate the current in the circuit
- 8. Heating a pot of water with an electric heater with resistance R1 takes t1min to boil, and heating the same pot of water with an electric heater with resistance R2 takes t2min to boil. The time ratio of heating the same pot of water with two resistors in series to heating the same pot of water with two resistors in parallel is () and the power supply voltage remains unchanged A t1+t2/t1t2 B (T1 + T2) square / t1t2 C t1t2/t1+t2 D T1 + T2 / (T1 + T2) square
- 9. The resistance of a resistance wire is 1000 ohm. The maximum allowable voltage is 1a. When the voltage is 220 V, how to make a maximum power electric heater
- 10. An electric fan, a TV set and an electric iron with the specifications of "220 V & nbsp; 100 W" are respectively connected into the 220 V circuit. The power on time is the same, and the heat generated by the current passing through them is the most: () A. Electric iron B. TV C. electric fan D. as much
- 11. In that year's senior high school entrance examination, the power supply voltage was 4.5V in the experiment of "measuring the electric power of small bulbs" The rated voltage of the small bulb is 2.5V and the resistance is about 10 Ω
- 12. If the voltage applied to both ends of a fixed value resistor increases from 6V to 10V and the current through the resistor changes by 0.1A, the electric power of the resistor changes () A. 0.6WB. 1.6WC. 2WD. 3.4W
- 13. Connect an electric heater to a 10V DC power supply and boil a pot of warm water in t time. Now connect the electric heater to an AC power supply of u = 10sin314tv Connect an electric heater to a 10V DC power supply and boil a pot of warm water in t time. Now connect the electric heater to an AC power supply of u = 10sin314tv and boil the pot of warm water in t time______ If it takes T / 3 to connect to another AC power supply, the maximum value of this AC power supply is______ .
- 14. When an electric heater is connected to a 100V DC power supply and consumes electric power P, if it is connected to a sinusoidal AC power supply and consumes power P / 9 (less than the influence of temperature and resistance), the maximum value of the sinusoidal AC voltage is? I get (100 √ 3) / 3
- 15. When a certain electric heater passes 5A current, it will produce 6.6 times ten quartic joules of heat per minute. Calculate the electric power, resistance and working voltage of resistance wire Come on. It's for tonight,
- 16. If the resistance ratio of the two electric heaters is 3:2 and they are connected to the lighting circuit, and they all work normally, what is the ratio of heat generated by them and the ratio of work done by the current in the same time?
- 17. What does the efficiency of electric energy into heat energy mean in science! Under standard atmospheric pressure, how much heat is absorbed by the water in an electric water heater when it boils 10kg water at 20 ℃? This is 3360000 (3.36 × 106) J Then the next question says, how much work should the current do? When the teacher talked about the test paper, he said that the efficiency of converting electric energy into heat energy of the electric water heater is 70%, which means that the electric water heater converts 70% of the consumed electric energy into heat energy, and then asks us to convert 3360000j / 70% into the work done by the current But the reason why an electric water heater boils water is heat transfer. The result of heat transfer is isothermal. When the water rises to 100 ℃, the electric water heater itself has to have a temperature of 100 ℃. Then the electric water heater itself has to absorb heat in order to transfer the heat to water. When the water rises to 100 ℃, it has to supply all the heat. So, the principle of heat transfer of the electric water heater itself is not the same···· By the way, the chemistry teacher recently asked us to write the chemical formula of CaCO3 + HCl, and then said that it should be CaCl2 + H2CO3 But because carbonic acid is easy to decompose, it is written as CaCl2 + H2O + CO2. But I think CO2 will become carbonic acid when encountering H2O····· CO2 + H2O = H2CO3. It's written in the book. That's what the science book says. There's this equation
- 18. An electric heater is connected to a power supply with a voltage of 220 V, and the current passing through the electric heater is 5 a
- 19. The dial of a household electric energy meter is marked with the word "600r / kW · H". When only one electric appliance is connected to the circuit and it works normally, the rated power of the electric appliance is () A. 3600WB. 1000WC. 500WD. 100W
- 20. The dial of an electric energy meter is marked with the words "1200R / kW · H", and an electric furnace is connected to the meter to work alone. 2. When the turntable of the electric energy meter turns 110 revolutions, how much electric energy does the electric appliance consume during this period? What is the resistance of the electric furnace when it works