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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?
High school physics ah! Again: resistance can be calculated directly through pz220-60, and then according to the actual power of 55wr can get the actual voltage, and then according to the voltage difference to get the voltage drop of the wire, combined with the actual current of the filament bead can get the power consumption of the wire!
The power supply is 220 V to a lamp marked "PZ 200-100" in a distant construction site. Due to the resistance of the wire, the actual work consumed by the bulb is very small
The power consumed by the conductor () A. is less than 5W B. is equal to 5W C. is greater than 5W
D. Not sure
Choose C
Take the wire as an electrical appliance. Connect it in series with a light bulb
The power is 95, less than the rated value, indicating that the bulb voltage is less than 200, then the voltage on the wire is greater than 20
The series current is equal, so the power of the wire must be greater than 0.1 times of the power of the bulb, that is, greater than 9.5, then it must be greater than 5
There are two light bulbs connected in series on the 220 V power supply, one is 220 V, 25 W, the other is 220 V, 40 W. which light is on? (list the formula needed to solve the problem)
W=U(2)/R→ R=U(2)/W
Under the rated voltage, the resistance is inversely proportional to the power, so the resistance of 25W is large
The voltage of the series circuit is proportional to the resistance, so the 25W bulb is brighter
(2) It's Square
Two bulbs A and B with nominal values of "220 V, 100 W" and "220 V, 25 W" are connected to the circuit in series
(1) What is the maximum allowable voltage?
(2) What is the sum of the actual maximum power of the two lamps?
R1 = 220 ^ 2 / 100 = 484 Ω, R2 = 220 ^ 2 / 25 = 1936 Ω, R1 / (R1 + R2) = 1 / 5r2 / (R1 + R2) = 4 / 5, two lamps are connected in series, and the voltage is proportional to the resistance. If the voltage at both ends of R1 is large, the voltage of R1 should not exceed. If the voltage of R1 can reach 220 V, the maximum allowable voltage is 220 * (5 / 4) = 275 VL
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- 1. Low voltage 24 V LED lamp connected to the protection of 220 V power supply will burn out
- 2. Connect two light bulbs marked with 220v100w and 220v60w in series to the 220 V power supply. What is their actual power,
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- 11. In festivals, we install colored lights. Now we have dozens of colored light bulbs on hand. When we work, the voltage at both ends is not more than 6.3V. We can only use the home circuit to supply power. The feasible way is () A. Connect 34 lights in series to the circuit B. connect 34 lights in parallel to the circuit C. connect 35 lights in series to the circuit D. connect 35 lights in parallel to the circuit
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- 13. Bulbs L1 and L2 are respectively marked with the words "220V 25W" and "220V 15W". If the two bulbs are connected in series and connected in the home circuit, the voltage ratio of the two lamps is______ What is the ratio of the current passing through______ What is the ratio of the actual power consumed______ The brighter light is______ If they are connected in parallel in a home circuit, the voltage ratio of the two lamps is______ What is the ratio of the current passing through______ What is the ratio of the actual power consumed______ The brighter light is______ ．
- 14. After connecting two "220 V, 60 W" bulbs in series and connecting them at both ends of the 220 V circuit, what is the actual total power of the two lamps?
- 15. There is a rated voltage of 220 V, power 100 W incandescent lamp, 5 hours a day, 30 days how much electricity?
- 16. How much is the rated current of two 220 V 100 W bulbs connected in series in 220 V circuit?
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- 18. Two models of "220 V, 40 W" and "220 V, 60 W" incandescent lamps are connected in series in the home circuit, and their actual electric power is calculated
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