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The electric iron marked with "220 V, 50 W" is connected to the 220 V power supply, and the heat generated per minute is______ J. One hour power consumption______ Degree
The electric iron is a pure resistance, ∵ P = 50W, t = 1min = 60s, ∵ the heat generated per minute is w = Pt = 50W × 60s = 3000j, and ∵ T1 = 1H = 3600s, ∵ the electric energy consumed for 1H is w = pT1 = 50W × 3600s = 180000j = 0.05kw · H = 0.05 degree
What should we pay attention to when measuring electric energy with electric energy meter and stopwatch
First of all, we should understand how to calculate the electric energy, q = Pt, P is the power, t is the time. P = UV, we deduce q = UVT, where u and V are measured with a multimeter (also can be measured directly with a power meter), t is measured with a stopwatch. Since it is measured with a meter, we first estimate the range, select the appropriate range, and the general measurement results of a digital meter are close to full deviation comparison
Resistance 55, voltage 220, working normally for 100s
Q=I²Rt=U²t/R=(220V)²*100s/55Ω=88000J
The name plate of an electric rice cooker is marked with "220V 1600W. If the actual voltage is 210v, what is the actual current in the electric rice cooker? What is the actual power? What is the power
The name plate of an electric rice cooker is marked "220V 1600W
(1) How much heat does this electric cooker produce when it works normally for 20 minutes?
(2) If this electric cooker works normally for 10 hours, how much power will it consume?
(3) What's the resistance of this rice cooker?
(4) If the actual voltage is 210v, what is the actual current and power in the rice cooker?
(1) Heat q = Pt = 1600W * 20min * 60s = 19200j (joule)
(2) Electric energy w = Pt = 1600W * 10h = 16000wh = 16kWh = 16kWh
(3) Resistance R = u ^ 2 / P = 220 V ^ 2 / 1600 w = 30.25 Ω
(4) Actual current I = u / r = 210v / 30.25 Ω = 6.94a
P=UI=210V*6.94A=1457.4W
RELATED INFORMATIONS
- 1. An experimental group has made a "220 V & nbsp; & nbsp; 22 W" electric iron, which can produce heat every minute when used under rated voltage______ J. The resistance of the electric iron is______ Ω．
- 2. An electric heater marked with "220 V, 500 V" (commonly known as "fast heating") can generate heat of 15 minutes after normal operation___ J. If all the heat released by the electric heater is absorbed by water, under standard atmospheric pressure____ Heat 2kg water at 20 ℃ to boiling
- 3. The rated power of an electric rice cooker is 800W. It is known that cooking rice requires 4.8x10 quintic joules of heat. If the electric rice cooker does not consider the loss of energy during normal operation, how long does it take to cook rice with it?
- 4. There are nine fluorescent lamps, a water dispenser and a TV in the classroom. What are their connection methods?
- 5. The rated voltage of a DC motor is 220 V and the rated power is 5.5 kW. How big is the current when it works normally? What is the power consumption for 2 hours continuous operation?
- 6. Is the power consumption of a 2W resistor 2W? If so, is the power consumption of 100 resistors connected in series 200W?
- 7. Human life needs energy. The following energy is mainly produced by chemical changes A. The heat required by electric kettle to boil water B. the electric energy generated by hydropower station using hydraulic power c. the heat energy generated by the burning alcohol lamp D. the wind energy used by wind power station
- 8. When someone is using an electric iron, in order to facilitate ironing and not make the temperature rise too high, the electric iron is usually connected to the circuit as shown in the figure. When should the switch s be closed and opened? What are the benefits of doing this?
- 9. The resistance of a bulb is 440 ohm, which is connected to the lighting circuit, and the current through the bulb is 440 ohm____ A. Power on 1H, this bulb consumes a lot of energy___ Electric energy of J The formula and process should be used
- 10. There is a "220 V 500 W" electric furnace, connected to the 220 V circuit, 0.4 hours to consume --- degree of electricity, the current through the circuit wire is --- A, the current in 1 s to do --- work
- 11. The rated voltage of electric iron is 220 V, the resistance working under the rated voltage is 1210 Ω, the rated power is calculated, and how much heat is there after passing through 10 minutes under the rated voltage?
- 12. If the brightest voltage of the lamp is 220 V and the working current is 0.18 a, what is the resistance of the filament when the voltage is 110 V If the title resistance or something is still unclear A is equal to 1222 B is equal to 611 C is greater than 1222 D is less than 1222
- 13. Connect the 220 V, 100 W small bulb to both ends of the 200 V power supply, can the small bulb work normally? What is the actual power of the bulb at this time?
- 14. A lamp marked with "220V 18W" is connected to the power supply If the current passing through the lamp is 1a, what is the actual power of the lamp? A18W B12W C8W D4W
- 15. When an electric lamp is connected to a 220 V power supply, its power is 100 W. if the power supply is connected to a long wire and then connected to the lamp, its power is 81 W, then the power consumed on the wire is 100 W______ W．
- 16. There is a festival lantern made of 20 small bulbs in series. If the current at the power plug is 200mA, then the current through each small bulb is 200mA______ mA．
- 17. Which lamp is brighter when it is connected to the 220 V power supply after it is connected in series with the 220 V 40W lamp A and the 220 V 100W lamp B
- 18. Connect two light bulbs marked with 220v100w and 220v60w in series to the 220 V power supply. What is their actual power,
- 19. Low voltage 24 V LED lamp connected to the protection of 220 V power supply will burn out
- 20. From the power supply with voltage of 220 V to an electric lamp marked "pz220-60" in a distant construction site, because the power supply wire has resistance The actual power consumed by the bulb is 55W. Then 1. The resistance of the filament? 2. The actual voltage at both ends of the bulb? 3. The electric power consumed by the wire?