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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.
Because after replacing the 10 ohm resistance between a and B with the 20 ohm resistance, the voltage of the 20 ohm resistance is larger than the original one. Now we are exploring the relationship between the current and the resistance, so the voltage should remain unchanged. When the sliding rheostat moves to the right, the voltage at both ends of the 20 ohm resistance will decrease to the original voltage (control variable method), and then the data can be recorded
In the experiment of exploring the relationship between the current in the conductor and the voltage at both ends of the conductor, Xiao Ming conjectured that the current in the conductor was also related to the resistance of the conductor, so Xiao Ming
In the experiment of exploring the relationship between the current in the conductor and the voltage at both ends of the conductor, Xiao Ming conjectured that the current in the conductor is also related to the resistance of the conductor, so Xiao Ming designed the following exploration experiment: the equipment available for the laboratory is as follows: 6V regulated power supply, "30 Ω 1A" sliding rheostat, ammeter, voltmeter, switch each; 5 Ω, 10 Ω, 15 Ω, 20 Ω fixed resistance each One; several conductors. (1) figure a is a part of the experimental circuit connected by Xiao Ming to explore "the relationship between the current in the conductor and the voltage at both ends of the conductor". Please connect the physical circuit in figure a completely, and the wires are not allowed to cross. (2) The physical quantity that should be controlled in this experiment is__________________ What are the physical quantities that need to be changed___________ (3) In order to explore the relationship between the current in the conductor and the resistance of the conductor, Xiao Ming should change the slide of the sliding rheostat to p direction after changing the resistance from 5 Ω to 10 Ω_______ End to end movement. (4) In this experiment, the voltage at both ends of the resistor should be kept the same, but if the control voltage is unreasonable, the experiment can not be completed. So Xiaoming to complete this exploration experiment, he should control the voltage at________ V to_________ Within the range of V. (5) If Xiaoming uses a resistor to do the experiment, after closing the switch, he finds that the ammeter has no real number, and the voltmeter shows 6V, then the circuit fault may be caused___________________ There is only one fault in the circuit. (6) After the correct operation, Xiao Ming drew the I and R images as shown in the figure, and the conclusion can be drawn from the images is: uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu.
(2) The physical quantity that should be controlled in this experiment is__ (resistance)___ What are the physical quantities that need to be changed___ (voltage)___ (3) In order to explore the relationship between the current in the conductor and the resistance of the conductor, Xiao Ming should change the slide of the sliding rheostat to p direction after changing the resistance from 5 Ω to 10 Ω__ Increase the resistance of the sliding rheostat__ (4) in this experiment, the voltage at both ends of the resistor should be kept the same, but if the control voltage is unreasonable, it will not be able to complete the inquiry experiment. So Xiao Ming should control the voltage at__ （2.4）__ V to__ （6）__ (5) if Xiaoming uses a certain resistor to do the experiment, after closing the switch, he finds that the ammeter has no real number, and the voltmeter shows 6V, the circuit fault may be caused__ (this resistor is open)__ (there is only one fault in the circuit). (6) after the correct operation, Xiao Ming drew the I and R images as shown in the figure__ (when the voltage is constant, the current is inversely proportional to the resistance)__ .
In the circuit shown in the figure, the power supply voltage is constant, and the bulb L is marked with "6V & nbsp; The maximum resistance of the sliding rheostat R is 120 Ω, and the range of the voltmeter is 0-15v. When the indication of the voltmeter is 8V, the bulb lights normally, ignoring the influence of temperature change on the bulb resistance (1) Power supply voltage U (2) when the resistance value of the sliding rheostat connected to the circuit is 25 Ω, the actual power consumed by the bulb (3) under the condition of not exceeding the rated voltage of the bulb and the range of the voltmeter, the change range of the resistance value of the sliding rheostat connected to the circuit
(1) From P = UI: I = Pu = 0.5A, the voltage on R0 is U0 = ir0 = 0.5A × 8 Ω = 4V, the total voltage is u = UL + U0 + U1 = 18V; (2) from P = u2r: RL = u2p = 12 Ω, from I = ur: I1 = URL + R0 + R1 = 18v45 Ω = 0.4A, the actual power of the bulb is PL = I2R = (0.4A) 2 × 12 Ω = 1.92W; (3)
A small light bulb marked with "6V, 3W" is connected to the circuit as shown in the figure. Assuming that the power supply voltage and filament resistance are constant, we can find: (1) what is the resistance of the small light bulb when it normally lights up? (2) When the resistance of the sliding rheostat connected into the circuit is 6 Ω, the small bulb can light normally after closing the switch. What is the power supply voltage? (3) If you change a power supply and a bulb with a rated voltage of 8V, when the switch S is closed and the slide P of the sliding rheostat slides to the midpoint C, the bulb will normally light up. At this time, the electric power of the bulb is p. when the slide P slides to the B end, the actual power of the bulb is p ′, and it is known that P: P ′ = 16:9? (let the voltage and filament resistance of the power supply remain unchanged & nbsp;)
(1) The resistance of the bulb: RL = U2, P = (6V) 23W = 12 Ω; (2) the current in the circuit: I = u, RL = 6v12 Ω = 0.5A, the voltage of the power supply: u = I (RL + RP) = 0.5A × (12 Ω + 6 Ω) = 9V; (3) when the switch S is closed, the slide P of the sliding rheostat slides to the midpoint C
RELATED INFORMATIONS
- 1. 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
- 2. 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
- 3. 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?
- 4. 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
- 5. 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
- 6. 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?
- 7. 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
- 8. Without changing the power supply voltage, please design a circuit diagram to change the brightness of the bulb
- 9. 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
- 10. 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?
- 11. 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?
- 12. When exploring the relationship between the current on the resistance and the voltage at both ends, what should be kept unchanged?
- 13. 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
- 14. 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,
- 15. In the experiment of studying the relationship between current, voltage and resistance, what is used to control the current in the circuit
- 16. In the experiment of exploring the relationship between current and voltage, resistance, when exploring the relationship between current and resistance, we should () A. Adjust the sliding rheostat to keep the current in the circuit constant B. Adjust the sliding rheostat so that the voltage at both ends of different fixed resistor R remains unchanged C. Make the voltage at both ends of resistance R change in multiple D. The current in the circuit should be changed in multiple during each measurement
- 17. If the voltage U and the resistance R are doubled simultaneously in a circuit, how will the power change? P = the square of (2U) divided by 2R Why is the square of (2R) divided by R
- 18. How does the change of resistance of sliding rheostat affect the change of voltage This is the eighth edition of Zhejiang Education Press. May I ask why the voltage of sliding rheostat in the circuit (series or parallel) changes? Why does the resistance of constant value resistor not change but affect the voltage? Does sliding rheostat affect the current, resistance and voltage? Another question: which factors are related to the brightness of the bulb? Current, voltage or resistance? There must be a lot of additional points!
- 19. How to change resistance current and voltage with sliding rheostat in series circuit? How to change resistance current and voltage with sliding rheostat in parallel circuit
- 20. How to change resistance, current and voltage in series / parallel circuit? The sliding rheostat changes the resistance in the circuit. How do the current and voltage at both ends of the planting resistor change? How do the total voltage and current change?