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___

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___

Let I1 = U1 / R, I2 = U2 / R
I2-I1=0.2 U2-U1=0.4
I2-I1= U2/R - U1/R
R = (u2-u1) / (i2-i1) = 2 Ω

In the experiment of measuring resistance with voltmeter and ammeter, the slide of sliding rheostat is moved, and it is found that when the voltage representation increases from 1 V to 3 V, the resistance of the sliding rheostat is increased,
It is found that when the voltage indication increases from 1 V to 3 V, the current indication changes by 0.4 a, then the resistance value of the measured resistance is () ohm, and the electric power of the resistance changes by 'W

5 ohm, 0.8 Watt
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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--

Let I1 = U1 / R, I2 = U2 / R, i2-i1 = 0.2, u2-u1 = 0.4, i2-i1 = U2 / R - U1 / R, r = (u2-u1) / (i2-i1) = 2 Ω

As the circuit shown in the figure, when closing and closing s, and moving the slide plate P of the sliding rheostat to the B end, the indication change of the voltmeter and ammeter is ()
A. When the voltage indication increases, the current indication decreases. B. both the voltmeter and the current indication increase. C. both the voltmeter and the current indication decrease. D. when the voltage indication decreases, the current indication increases

When the slide plate P of the sliding rheostat moves to the B end, the resistance of the R access circuit decreases, and the total resistance of the circuit decreases. According to Ohm's law of closed circuit, if the current in the circuit increases and the internal voltage of the power supply increases, the voltage at the end of the circuit decreases, so the voltage representation decreases and the current representation increases

A student did the experiment of "measuring resistance with ammeter and voltmeter". The optional equipment are: 2 power supplies (voltage is 6 V and 4.5 V respectively), 2 sliding rheostat (marked with "10 Ω 3A" and "20 Ω 3A" respectively) He chose the equipment, connected the circuit according to the diagram, and the steps were correct. He closed the key, and found that the ammeter's indication was 0.2 A. then (1) the power supply voltage selected by the student in the experiment was______ The maximum resistance of the sliding rheostat selected is______ (2) when the student moves the slide of the sliding rheostat to the midpoint (that is, the resistance connected to the circuit is half of the maximum value of the rheostat), the ammeter shows 0.24 a, and the voltmeter shows v______ He continued to move the slide of the sliding rheostat, and found that the maximum current in the circuit was 0.3 A. at this time, the voltmeter V was______ The resistance value of Rx to be measured is______ Oh

(1) ∵ I = ur ∵ the voltage at both ends of the circuit may be: U1 = I (Rx + R1) = 0.2A × (19 Ω + 10 Ω) = 5.8v; U2 = I (Rx + R2) = 0.2A × (19 Ω + 20 Ω) = 7.8v; therefore, the selected power supply voltage is 6V; the maximum resistance of the selected sliding rheostat is 10 Ω; (2) ∵ I = ur ∵ when the slider reaches the middle point, the voltage at both ends of the sliding rheostat: ur = I '× 12R = 0.24a × 12 × 10 Ω = 1.2V, and ∵ I = ur The voltage at both ends of the connecting circuit is equal to the sum of the voltages of each part. The indication of the voltmeter V is: UX = 6v-1.2v = 4.8V; when the current indication is the maximum, the resistance of the sliding rheostat connected to the circuit is zero, then the voltage indication is equal to the power supply voltage, that is, 6V; RX = UI ″ = 6v0.3a = 20 Ω. So the answers are: (1) 6; 10; (2) 4.8; 6; 20