![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Two resistors R1 and R2 are connected in parallel in the circuit. If the current I1: I2 passing through the resistor R1 and R2 is 4:3, the voltage ratio at both ends of the resistor R1 and R2 is () A.4:9 B：1:1 C.3:2 D.2:3
B;
In parallel, the voltage at both ends is equal, and the series current is equal;
If you have any questions, please ask!
R1 = 3 ohm, R2 = 4 ohm two resistors are connected in parallel in the circuit. After being electrified, what is the heat ratio Q1 / Q2 at the same time? What is the current ratio I1 / I2
Parallel circuit, branch voltage equal
So Q1: Q2 = P1: P2 = u ^ 2 / R1: u ^ 2 / r2 = R2: R1 = 4:3
I1:I2=U/R1:U/R2=R2:R1=4:3
As shown in the figure, R1 = 5 ohm, R2 = 20 ohm. It is known that the current I1 passing through R1 is 0.4A. Calculate the voltage at both ends of the circuit and the current passing through resistance R2
As shown in the figure, the resistance value of resistance R1 is 5 ohm, the current in the trunk circuit is 0.5A, and the voltage at both ends of resistance R2 is 2V. Calculate (1) the current passing through R1 (2) the current passing through R2 (3) the resistance value of R2
(1) Because the two resistors are in parallel:
U1=U2=2V
According to Ohm's Law:
I1=U1R1=2V5Ω=0.4A；
(2) According to the current law of parallel circuit, it can be seen that:
I2=I-I1=0.5A-0.4A=0.1A；
(3) The voltage and current of R2 are 2V and 0.1A respectively;
Then the resistance of R2:
R2=U2I2=2V0.1A=20Ω；
A: (1) the current through R1 is 0.4A; (2) the current through R2 is 0.1A; (3) the resistance of R2 is 20 Ω
The unknown resistance R and 20 ohm resistance R1 are connected in series to the power supply, and the measured current through R1 is I1 = 0.4A. Then R and 50 ohm R2 are connected in series to the same power supply
Regardless of R, R2 increases by 2.5 times from 20 to 50, because r remains unchanged, u remains unchanged, so the total resistance increases by 2.5 times, the current decreases by 2.5 times, 0.4 / 2.5 = 0.16A. OK, 100% is like a fake replacement!
RELATED INFORMATIONS
- 1. In equilateral triangle circuit, corresponding to three resistors, known as U1 = U2 = U3 = 380V, R1 = R2 = R3 = 48 ohm, calculate I1, I2, I3
- 2. The unit of force is, abbreviated as, symbol
- 3. It is often used in science to show force directly
- 4. Physics of grade two (about force) The lovely Fuwa is having a sports match. The following is the statement about these scenes ..（ ） A when swimming, the force of the hand on the water keeps Beibei moving forward When B Beibei and Nini rowed, the rowing boat received a forward force, which had no force object When playing volleyball, Nini changed the shape of volleyball and the movement state of volleyball When playing football, the foot gives the ball a kick, and then the ball gives the foot a kick What? Why? Why is c good?
- 5. The traffic police on duty on the Jingchang Expressway stopped a speeding car. After saluting the driver, the traffic police said, "your speed exceeds the limit of 120 km / h". Before the traffic police finished, a child in the car said, "we only drove for a few minutes, and we didn't have to wait If you are the traffic policeman, how can you explain to the children?
- 6. Letters and physical quantities What letter stands for what physical quantity? Where is all I want all of them. I don't want to introduce them. Just give the letters
- 7. For the formula 1 / F = / F1 + 1 / F2 (F2 ≠ 2f), if f and F2 are known, the deformation result of the formula is
- 8. Convex lens imaging, drawing: ① 0 ＜ u ＜ F, ② u = f, ③ f ＜ u ＜ 2F, ④ u = 2F, ⑤ u ＞ 2F, ⑥ 0 ＜ u ＜ F, ⑦ u = 3fu = 5F, f = 2cm
- 9. Image appearance when u ＜ F, u ＞ 2F, u = f, f ＜ u ＜ 2F, u = 2F
- 10. Objects near the earth's surface must be affected by gravity, right?
- 11. After resistor R1 and R2 are connected in parallel, they are connected to the power supply with voltage u, and the main circuit current is I. The current passing through R1 and R2 is I1 and I2 respectively. It is tried to prove that I1 = [R2 / (R1 + R2) Try to prove that I1 = [R2 / (R1 + R2)] I That is to say, I1 is equal to R2 divided by the sum of R1 and R2, and then multiplied by I}
- 12. The power supply voltage is 6V, the resistance R1 = 5 ohm, and the maximum resistance of rheostat R2 is 10 ohm Find out the change range of voltmeter and ammeter
- 13. Two fixed value resistors R1 and R2 are connected in parallel and connected to the circuit. Their electric power is P1 and P2 respectively, and the total power is p. try to prove that P = P1 + P2
- 14. If the two constant resistors R1 and R2 are connected to the power supply in some way, the power consumed by R1 is 9W, If the two resistors are connected to the power supply in another way, the power consumed by R1 is 16W, and the current passing through R2 is 4a. If the power supply voltage remains unchanged, what is the power supply voltage and the resistance of r1r2
- 15. Connect two fixed value resistors in series to both ends of the power supply with voltage of u, the power consumed by R1 is P1, and the power consumed by R2 is 3P1 A. The ratio of voltage between R1 and R2 in series is 3:1b. The power consumed by R1 in parallel is 16p1c. The ratio of current through R1 and R2 in parallel is 1:3d. The total power consumed by two resistors in parallel is 163p1
- 16. If resistance R1 is connected to a circuit, the power consumed is P1; if another resistance R2 is connected to the same circuit in series, the power consumed by R2 is P2. If P1: P2 = 4:1, R1 "select" greater than "," less than ", or" equal to "R2
- 17. There are three resistors, R1 = 8 ohm, R2 = 12 ohm, R3 = 20 ohm. Connect them in series with a 10 volt power supply. What is the voltage at both ends of the three resistors?
- 18. A small electric bell with a resistance of 10 ohm is connected in series with a fixed resistance of 20 ohm and connected to a 6V power supply. If the small electric bell just works normally, what is the voltage at both ends of the electric bell?
- 19. Generally speaking, when the load resistance decreases, the load increases, and the power output power increases (×), how to explain
- 20. The electromotive force of the power supply is 2V and the internal resistance is 0.1 ohm. When the external circuit is open, the current and terminal voltage in the circuit are