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In order to explore the "relationship between electric power and resistance", Li Ming found two lamps L1 and L2 with the rated voltage of 6V. He connected the two lamps in series and started the experimental exploration according to the circuit shown in the figure. After closing the switch, he saw that the lamp L2 was slightly luminous, while the lamp L1 was almost not luminous. Then the relationship between the resistance R1 and R2 of the two lamps, and the rated power P1 and P2 of the two lamps was established (not applicable) Consider the change of filament resistance value with temperature) () A. R1＞R2，P1＞P2B. R1＜R2，P1＜P2C. R1＞R2，P1＜P2D. R1＜R2，P1＞P2
The brightness of the bulb is determined by the actual power of the bulb, because the lamp L2 emits a little light, and the lamp L1 hardly emits light, so the actual power of L2 is greater than that of L1. Because the two lamps are connected in series, according to P = I2R, under the same current, the electrical power of the consumer is proportional to the resistance, so R2 > R1, The electric power is inversely proportional to the resistance. Because R1 < R2, P1 > P2
Relationship between power distribution and resistance in series and parallel
P=I^2*R
In series, the current is the same, so in series, the power is proportional to the resistance
That is to say:
P1/P2=R1/R2
At the same time, P = u ^ 2 / R
In parallel, the voltage is the same, so the power is inversely proportional to the resistance
That is to say:
P1/P2=R2/R1
RELATED INFORMATIONS
- 1. 1. Two resistors with the same organization are connected in series first and then in parallel, respectively in the circuit with the same voltage. What is the ratio of the total power of series and parallel?
- 2. The bulb and a resistor are connected in series to the power supply. The power of the lamp is 81w, and the power of the resistor is 9W. If the lamp is directly connected to the power supply, it will light normally Calculate the rated power of the lamp
- 3. Without changing the power supply voltage, please design a circuit diagram to change the brightness of the bulb
- 4. To enable the rheostat to control the brightness of the bulb, should the rheostat be connected in series or in parallel with the bulb It controls the brightness of the light bulb
- 5. A light bulb and a sliding rheostat are connected in parallel in a circuit to increase the resistance of the sliding rheostat. Does the light bulb turn on or dark?
- 6. How to find the resistance of light bulb?
- 7. When exploring the relationship between the current and voltage on the resistance, the sliding rheostat changes the voltage at both ends of the light bulb, while the book says that the voltage of the small light bulb is larger, There's a lot of current in the circuit, but I feel it doesn't matter
- 8. Whether a small light bulb emits light depends on what? Rated voltage, rated current or resistance, or rated power
- 9. When the voltage at both ends of the resistor increases from 2V to 4V, the current intensity through the resistor changes by 0.25A, Then the resistance of the constant resistance ro is____ Ohm. The electrical power of the resistance ro increases____ w. This is to fill in the blanks!
- 10. DC power supply 5V need resistance to step down to 4V, limit current in 4.5a need a few w several r resistance?
- 11. A light bulb is marked with "4V, 4W". After it is connected in series with a constant resistance R, it is connected into the circuit with the power supply voltage of 6V. When the switch is closed, measure the A bulb is marked with the words "4V, 4W". After it is connected in series with a constant resistance R, it is connected to the circuit with the power supply voltage of 6V. When the switch is closed, the measured power consumption of R is 2W. At this time, the bulb does not light normally. Regardless of the influence of temperature on the resistance value of the bulb, calculate: 1 the resistance value of the constant resistance R, 2 the incident electric power of the bulb
- 12. The lamp and a resistor R are connected in series and then connected in a circuit with voltage of U. the current flowing through the lamp is I, and the electric power consumed by the lamp is?
- 13. In the circuit shown in the figure, the power supply voltage remains unchanged. There may be faults in resistance R and lamp L. before and after the key s is closed, the position of ammeter pointer remains unchanged. The correct judgment in the following is () A. If lamp L does not light up, only resistance R is short circuited. B. If lamp L does not light up, only resistance R is open circuited. C. If lamp L lights up, only resistance R is short circuited. D. if lamp L lights up, only resistance R is open circuited
- 14. As shown in the figure, the light bulb L is marked with "6V 3W", and the power supply voltage remains unchanged. When the switch is closed, the resistance of the sliding rheostat connected to the circuit is 4 Ω, and l lights normally, the power supply voltage is 0_____ 5. If the total power consumed by the circuit is 3.2w by changing the position of slide plate P of the sliding rheostat, then the actual power of the small bulb is___ W A graph is a series
- 15. In order to explore the relationship between current and resistance, Xiao Ming replaced the 10 ohm resistance between a and B with 20 ohm resistance as shown in Figure 8. After closing the switch, the next operation should be () A. Record the indication of ammeter and voltmeter B. Move the sliding rheostat to the right C. Move the sliding rheostat to the left D. Increase the number of batteries appropriately B, why.
- 16. The specification of an electric iron is "220 V & nbsp; & nbsp; & nbsp; 110 W". Please answer the following questions: (1) what is the normal working current of the electric iron? (2) What is the resistance of the electric iron? (3) How much heat does it produce when it is electrified for 10 minutes at rated voltage?
- 17. When exploring the relationship between the current on the resistance and the voltage at both ends, what should be kept unchanged?
- 18. The resistance of a conductor is directly proportional to the voltage at both ends of the conductor and inversely proportional to the current passing through the conductor Why wrong? How to understand the relationship between resistance, voltage and current? Don't use books. It's suitable for multiple choice questions
- 19. Is the statement "when the resistance of a conductor is constant, the current is proportional to the voltage"? Those who are right should pay attention! I thought it was right, but the answer is wrong! I wonder if it should be said that when the resistance of a conductor is constant, the current in the conductor is proportional to the voltage at both ends of the conductor! I want to win your opinions,
- 20. In the experiment of studying the relationship between current, voltage and resistance, what is used to control the current in the circuit