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Why is the measured value greater than the true value when measuring the internal resistance error of ammeter with half bias method
The measured value is less than the true value. After a resistor is paralleled at both ends of the ammeter, the total resistance decreases, so the total current increases. Therefore, when the reading of the ammeter is I / 2, the current on the rheostat box is greater than I / 2, so the resistance measured by the rheostat box is less than the true value of the ammeter
The laboratory supplies one power supply, one ammeter and one voltmeter, two constant resistance R1 = 6 Ω, R2 = 4 Ω. (1) please choose three of them and fill them in the diagram with symbols to form four different circuits (a, B, C and D). It is required that all components of the circuit can work normally, and the power consumed by each circuit is p a > P B > P C > P D. (2) if The power supply voltage is 6V, calculate the total power of the circuit and the reading of the ammeter
(1) According to the characteristics of series and parallel connection of resistance, the relationship of resistance value obtained by the combination of resistance r1r2 is: R series > R1 > R2 > R parallel. When the voltage is constant, P = u2r can know: P parallel > P2 > P1 > P series, so the circuit diagram meeting the requirements of the question is shown in the right figure. (2) according to 1R = 1r1 + 1r2: R total = r1r2r1 + R2 = 6 Ω × 4 Ω, 6 Ω + 4 Ω = 2.4 Ω; according to P = u2r: p a = (6V) 22.4 Ω = 15W; according to I = ur: R total = r1r2r1 + R2 = 6 Ω × 4 Ω, 6 Ω + 4 Ω = 2.4 Ω I = 6v2.4 Ω = 2.5A. A: (1) the four different circuit diagrams that meet the requirements are shown in the figure above; (2) the total power of the circuit in figure a is 15W; the reading of the ammeter is 2.5A
There are two fixed value resistors R1 and R2 with unclear resistance. Here are the following equipment: power supply, a switch, a voltmeter and an ammeter. How do you compare the two resistors? & nbsp; comparison method with voltmeter: comparison method with ammeter:
The resistance R1, R2, parallel in the circuit, respectively, with an ammeter to measure the two branches, the current is large, the resistance is small; the current is small, the resistance is large
Connect the power supply, resistance R1 and R2 in series with wires, and then measure the two ends of resistance with voltmeter. If the voltage is large, the resistance is large; if the voltage is small, the resistance is small
For the circuit shown in the figure, the indication of voltmeter is 2V, the indication of ammeter is 1a, and the power supply voltage in the circuit is 5V. What is the resistance of R2?
According to the circuit diagram, R1 and R2 are connected in series. The voltmeter measures the voltage at both ends of R1 and the ammeter measures the current in the circuit. ∵ the total voltage in the series circuit is equal to the sum of the partial voltages, ∵ the voltage at both ends of R2: U2 = u-u1 = 5v-2v = 3V, ∵ I = ur, ∵ the resistance of R2: R2 = u2i = 3v1a = 3 Ω. Answer: the resistance of R2 is 3 Ω
RELATED INFORMATIONS
- 1. In the circuit shown in the figure, both ammeter and voltmeter are ideal ammeter, then the correct one in the following judgment is () --- the one that can understand (A) Rab = RBD, and RBC is the largest, RAC is the smallest, (B) Rab = RCD, and RBC is the largest, RAC is the smallest, (C) RAC = RCD, and RBC is the largest, RAD is the smallest, (D) RAC = RBD, and RBC is the largest, RAD is the smallest, -- see -- the answer is C. I don't quite understand. If the answer is the same, please forgive me for ignoring it
- 2. In the circuit, the resistance R1 is 10 Ω. Close the switch s, the indication of ammeter A1 is 0.3A, and the indication of ammeter A2 is 0.5A Ask: (1) current through resistance R2: (2) power supply voltage please write the process of solving the problem clearly
- 3. As shown in the figure, the power supply voltage remains unchanged. When the switches s and S1 are closed, the indication of the ammeter is 1a. When the switch S is closed and the switch S1 is open, the indication of the current is 0.6A. The ratio of the resistance value of resistance R1 to resistance R2 is () A. 3：2B. 2：3C. 5：3D. 3：5
- 4. A classmate didn't have an ammeter. He had a power supply voltmeter. The rheostat setting resistance R0 resistance was known. How to measure the small lamp with known rated voltage Experimental circuit diagram experimental steps need to measure the physical quantities and calculation formula! Hurry!
- 5. As shown in the figure, the power supply voltage U remains unchanged, and the indication of ammeter is 2A. Resistance R1 and R2 are in parallel, equivalent resistance R, and R1: r = 4:3, If the power consumed by resistor R2 is 2.5W. Find the power supply voltage
- 6. Explore the experiment (1) given a power supply, a voltmeter, a constant resistance (known its resistance), a number of switches and wires, try to design a circuit diagram It can measure the resistance of an unknown resistance according to certain steps You want to draw a picture for me~ In addition, the corresponding letters should be used to represent the physical quantities measured by the elder brother Represents each measured physical quantity Can you give me a picture
- 7. Give you a resistance, voltmeter, switch, power supply and wire with known resistance value. Please design an experiment to measure the resistance value of unknown resistance Rx. (1) draw the circuit diagram of the experiment. (2) write the experimental steps. (3) write the expression of Rx. (4) in addition to the method of substitution with known resistance, You can also use switch (or single pole double throw switch), sliding rheostat to solve the unknown resistance. Students use their brains to think, can you use other methods to measure the resistance of the unknown resistance?
- 8. There are the following equipment on the experimental table: a power supply, an ammeter and a voltmeter, a switch, a sliding rheostat, two resistance boxes, fixed resistance and wires with known resistance values. It is required to select appropriate equipment from the experimental table and design an experiment to prove: "when the voltage at both ends of the resistance remains unchanged, the electric power consumed by the resistance is the same as that consumed by the resistance The resistance of the resistance is inversely proportional. Please draw the experimental circuit diagram, write the experimental steps, and design the data recording form
- 9. What is the effect of changing the 100 ohm resistance in series with the ammeter to 200 ohm in the circuit diagram of superposition theorem on the measurement result
- 10. How to judge which electrical appliance is measured by Voltmeter and ammeter As the title I'm sorry. For example, if two switches are closed, which appliance is short circuited, and if two switches are open?
- 11. Why is it necessary to make the half deviation of pointer as big as R resistance when measuring the internal resistance of meter head with half deviation method
- 12. The full scale current of a Ma meter is 1mA, the internal resistance of the meter is 98 Ω, and the shunt resistance is 2 Ω
- 13. Can the ohm range of the multimeter be used to measure the internal resistance of the power supply and the micro ampere meter?
- 14. Why is the sliding rheostat connected by partial voltage in the experiment of drawing volt ampere characteristic curve of small bulb?
- 15. Pay attention when using ammeter
- 16. When measuring the current with a DC ammeter, if the reference direction is inconsistent with the actual direction, what will be displayed? How to correctly judge the measured current direction? Such as the title
- 17. How to know the electricity consumption of the meter in a month by measuring the current in front of the meter with a clamp ammeter?
- 18. The ammeter must be connected in series in the circuit to be measured. Under what circumstances is the ammeter connected in parallel in the circuit to be measured? Please use the circuit diagram. Also, I said in my book that the ammeter can't be directly connected in parallel with the consumer or ammeter. What's the circuit diagram in this case?
- 19. A series circuit. The ammeter is between two lamps. Which lamp's current is measured by the ammeter
- 20. When using the ammeter! Why do you need zero correction? If the measured current exceeds the range of the ammeter, what will happen!