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As shown in the figure is the relationship between the current I and the voltage U of the two resistors A and B. connect them into the circuit in parallel A. The current passing through a is greater than that passing through B. the current passing through a is less than that passing through B. the total resistance of a and B in parallel decreases with the increase of voltage at both ends. D. the total resistance of a and B in parallel increases with the increase of voltage at both ends
(1) From the I-U image, it can be seen that when the voltage at both ends of resistance a and resistance B is equal and the voltage is less than the intersection voltage, the current flowing through resistance a is greater than that passing through resistance B; when the voltage is greater than the intersection voltage, the current passing through resistance a is less than that passing through resistance B; therefore, when the voltage is small, the current passing through resistance a is greater than that passing through resistance B, and when the voltage is large, the current passing through resistance a is greater than that passing through resistance B The current of resistance a is less than that of resistance B, so AB is wrong; (2) according to the image, the resistance value of resistance B R B does not change with the change of voltage, which is a fixed value; according to Ohm's law r = UI, with the increase of voltage, the increase of current through resistance a is slower and slower, so the resistance value of resistance a r a increases with the increase of voltage, which can be seen from the characteristics of parallel circuit It is known that if 1R union = 1R a + 1R B, then r union = r a r b r a + R B = R B 1 + r b r A. from R union = R B 1 + r b r a, it can be seen that with the increase of voltage u, R B remains unchanged, and r a increases, then the parallel resistance R increases, so the total resistance of a and B increases with the increase of voltage at both ends, so C is wrong and D is correct. Therefore, D is selected
1. In a circuit, does the voltage increase with the increase of resistance? 2. In a circuit, if the current increases but the resistance decreases, the voltage at both ends will decrease
1. Does the voltage increase with the increase of resistance in a circuit?
2. In a circuit, if the current increases and the resistance decreases, will the voltage at both ends decrease?
For example: if the resistance of sliding rheostat becomes smaller, does the voltage at both ends also become smaller? Why not consider the increase of current?
Reference: 2009 Weifang high school entrance examination physics question 9
2009 Weifang high school entrance examination physics question 9
If you're sure it's for the senior high school entrance examination, I'll dare to answer it, because ordinary questions don't ask like this unless there is a certain language environment
1, not necessarily. If the current is constant, the resistance will increase and the voltage will increase
2. Maybe
In junior high school, if the resistance of the sliding rheostat becomes smaller, the current of the main road will become larger, and the voltage of other resistors will become larger, so the voltage of the sliding rheostat will become smaller. Pay attention to the relationship between the whole and the part
[chapter on current circuit voltage resistance]
1. Electroscope is to use________ It's made on the principle of
2. Electric appliance is a kind of equipment that uses electricity to work_____ Convert to_______ I can't help it
3. The characteristic of parallel circuit is the on and off of each branch_______ Each branch circuit and main circuit form a channel respectively
4. The voltage causes the charge in the circuit to move directionally, thus forming a________ Voltage is similar to water pressure
5__________ It's a device that supplies voltage
1. The same charge repels each other
2. Electric energy and other forms
3. No influence on each other
4. Current
5. Power supply
Who knows where to draw physical exercises about voltage, current and resistance circuit diagram (at least five)
It's the problem of drawing circuit diagram
To a just check the web site, you can type these words directly into it
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