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A voltmeter with an internal resistance of 1000 ohm has a measuring range of 3V. When a new voltmeter is assembled by connecting a 5000 ohm divider in series, the reading is 2V A voltmeter with an internal resistance of 1000 ohm has a measuring range of 3V. When it is assembled into a new voltmeter with a 5000 ohm partial resistance in series, the reading is 2V. What is the measured voltage? What is the measuring range of the new voltmeter? How much is the measuring range
When it is connected in series with a 5000 ohm divider resistor, a new voltmeter is assembled with a measuring range of 3 × (5000 + 1000) / 1000 = 18V
When the reading is 2V, the measured voltage is 18 × 2 / 3 = 12V
The range of voltmeter 15V is damaged, the range of 3V is normal, and the power supply voltage 6V remains unchanged. How to measure the resistance of small bulb with only the following instruments
--------Power supply (+) - --- switch s -- -!
--Sliding rheostat bulb l --- ammeter --!
-Voltmeter and - are wires)
The third exclamation mark (wire) on the second line should be at the end of the second line
The second exclamation mark is scribing
will connect a sliding rheostat (current mode), an ammeter and a small bulb. When the 0-3V voltmeter is connected with the slide rheostat in parallel, it will be connected to the 6V power supply. Note that when connecting, slide the rheostat to the maximum and tune it to the hour. The 6V voltage is all added to the small bulb and the small bulb will burn out. Then adjust the slip rheostat to make the voltmeter reading 2.2V. At this time, the voltage on the small bulb is 3.8V, and the small bulb lights normally. Read the reading of the ammeter again. This current is the rated current of the small bulb. Multiply this current by 3.8V, which is the rated power of the small bulb
How to choose voltmeter and ammeter when measuring resistance by voltammetry
It is known that RX = 10 ohm and I = 2.5A are used to measure resistance by volt ampere method, ignoring the influence of internal resistance of ammeter. In order to make the relative uncertainty of measured resistance less than 1.5%, what kind of ammeter and voltmeter should be selected
Ignoring the influence of internal resistance of the ammeter, the theoretical calculated voltage should be 25V, then the ammeter can choose 5A range and the voltmeter 100V range. Ordinary multimeter, digital one is OK, if the ammeter has a square meter, the error is small
RELATED INFORMATIONS
- 1. Using voltmeter and ammeter to measure the resistance of small bulb when it is normally emitting, what problems should be paid attention to
- 2. The sliding rheostat is connected in series with the ammeter and the lamp, and the lamp and the voltmeter are connected in parallel
- 3. There is a small bulb with a resistance of 10 Ω. When it lights normally, the voltage at both ends is 6V. Now there is only a 9V power supply Q: 1. How to connect a small light bulb to make it shine? 2. How much resistance do you need to give it? There are three ways to answer the second question!
- 4. There are two bulbs in series in the circuit. The voltage at both ends of bulb L1 is 3V, the total resistance of the circuit is 10 ohm, and the resistance of bulb L1 is 5 ohm (1) Resistance of bulb L2 (2) current in circuit (3) voltage at both ends of bulb L2 (4) supply voltage
- 5. A small bulb marked with "6V. 3W" is connected in series with a sliding rheostat with a maximum resistance of 30 ohm. When the resistance of the rheostat entering the circuit is 12 ohm, the lamp will light normally. When the resistance of the rheostat entering the circuit is 18 ohm, the bulb resistance and power supply voltage are calculated (2) Voltage at both ends of rheostat (3) Actual power of bulb
- 6. The small bulb marked "6V 3W" is connected in series with a sliding resistor with a maximum resistance of 10 ohm in the circuit. When the sliding resistor is connected to the circuit with a resistance of 6 ohm, the lamp will light normally Ask: 1: bulb resistance, power supply voltage? 2: How much heat does the sliding rheostat generate when the bulb lights normally for 1 minute?
- 7. The resistance of an electrical appliance is 100 ohm, and its maximum allowable current is 100 mA. If it is connected to a circuit with a current of 1.1 A, what method should be adopted?
- 8. The voltage at both ends of a circuit is 220 V, and the resistance of the consumer is 40 Ω. Can we use an ammeter with a range of 0 ~ 3a to measure its current?
- 9. How to know which electric current is measured by ammeter? I know which consumer the ammeter is connected in series with is to measure which consumer's current, but I just can't tell which consumer the ammeter is connected in series with. I don't know whether it's left or right!
- 10. The two lamps are connected in parallel, the known resistance R1 = 5 ohm, the main circuit current I = 0.5A, the voltage at both ends of R2 U2 = 2V, and the circuit current I = 0.5A The two lamps are connected in parallel, the known resistance R1 = 5 ohm, the driving current I = 0.5A, and the voltage at both ends of R2 U2 = 2V 1. Find the current through R1 2. Current through R2 3. Resistance of R2 It's a process. Thank you
- 11. In the circuit as shown in the figure, the power supply voltage is 9 V, the range of voltmeter is 0 ~ 3 V, the range of ammeter is 0 ~ 0.6 a, the setting resistance R1 = 20 Ω, and the sliding rheostat is marked with "15 Ω & nbsp; Calculation: ① when the reading of ammeter is 0.4 a, the voltage at both ends of resistance R1. ② the maximum resistance value of sliding rheostat R2 allowed to be connected into the circuit. ③ in order to make each ammeter reach the maximum value respectively in the process of moving slide, the appropriate fixed value resistance R is selected to replace the fixed value resistance R1 to find out the value range of r that meets the requirements
- 12. When 10V voltage is applied at both ends of a constant value resistor, the current passing through it is 0.4A. If 5V voltage is applied at both ends of the resistor, the current passing through the resistor is? A, What's the reason for your judgment?
- 13. As shown in the figure, U1 = 6V, u = 10V, the current passing through R1 is 0.4A, and the resistance of R1 R2 can be calculated The circuit diagram is patchy___________ I ————|_________ |——————|___________ |————＞—— R1 R2 |＜——U1——＞| |————U2——————＞| |＜——————————U————————————＞|
- 14. The voltage at both ends of the power supply is 6V, R1 and R2 are constant resistance. After closing switch s, the indication of ammeter is 0.2A, and that of voltmeter is 4V What are the resistance values of R1 and R2? Write out the process, too```
- 15. Han Yong designed the circuit as shown in the figure to measure the resistance value of resistance R1. When he contacts the switch with a and B respectively, the ratio of ammeter indication is 5:2. Given that R2 = 6 Ω, what is the resistance value of R1?
- 16. The power supply voltage is 6 V, the indication of ammeter A is 2.5 A, R1 = 4 Ω, calculate the indication of ammeter a1.a2 and the resistance of resistance R2 Well
- 17. When measuring resistance R by voltammetry, if the reading of ammeter is 0.2A and that of voltmeter is 30V, what is the resistance value of the resistance to be measured?
- 18. When Ohm's law is used to measure resistance, if the slide of sliding rheostat is moving, the degree of voltmeter will change from 1.2V to 1.6V, while the degree of ammeter will change from 1.2V to 1.6V—— When using Ohm's law to measure resistance, if the degree of voltmeter changes from 1.2V to 1.6V and the indication of ammeter increases by 0.2A, the resistance value of resistance R to be measured is___
- 19. As shown in the figure, during the movement of slide P of rheostat R0, the indication range of voltmeter is 0 ~ 4V, the indication range of ammeter is 1 ~ 0.5A, and the internal resistance of power supply can be ignored. Calculate the resistance value of resistance R, the maximum value of rheostat R0 and the electromotive force E of power supply
- 20. Use voltmeter and ammeter to measure resistance. Why use sliding rheostat in this experiment