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In a circuit with constant voltage, when the resistance is increased by 5 Ω, the current becomes four fifths of the original, then the original resistance is zero____ To change the current to the original value One third, another one should be connected in series______ The resistance of the sensor is high
Let the power supply voltage be u and the resistance be r. according to the meaning of the title, there are: [U / (R + 5)] / (U / R) = 4 / 5 R / (R + 5) = 4 / 5 r = 20 ohm [U / (25 + R1)] / (U / 20) = 1 / 3 20 / (25 + R1) = 1 / 3 R1 = 35 ohm, so a 35 ohm resistor should be connected in series
How much power can four square aluminum wires bear
One square multi strand aluminum wire is 6a, single strand is 5A. Power = voltage (V) x ampere (a)
An electric energy meter is marked with 600r per kilowatt hour. How much electric energy is consumed when the dial rotates 60R per minute? What is the electric power?
The sixth power of W = 60 / 600kW. H × 3.6 × 10 J / kW. H = 360000j
So the power consumption is 360000j
1 minute = 60 seconds
From P = w / T, P = 360000j / 60s = 6000W
So the power is 6000W
RELATED INFORMATIONS
- 1. The electricity meter of a classmate's home shows 052134 at the beginning of the month and 053032 at the end of the month, How many kilowatt hours of electricity does the student's family use in a month? How many joules is it equal to? If the price of electricity per kilowatt hour is 0.50 yuan, how much electricity will his family pay this month?
- 2. As the circuit shown in the figure, in the process of sliding plate P of sliding rheostat moving from end a to end B, the indication of ammeter () A. From big to small B. from small to big C. from big to small D. from small to big
- 3. How many watts and how many ohm resistance does it need to change 3.3 V DC power supply into 3.0 V DC power supply? The current is 1.4 to 1.5 a
- 4. With low-voltage DC power supply, the resistance of electrical appliances is constantly changing between 2000 ~ 6000 Ω. How to make a circuit with stable output current of 1mA? It is planned to use a single 9V or 12V battery as the power supply. The resistance value of the electric appliance changes greatly, so it is necessary to make 1mA current continuously pass through the electric appliance. It is better to add a regulating device so that the current can be adjusted between 1mA and 5mA, but when it is not adjusted, the current should be stable at a certain value, and the smaller the fluctuation is, the better. Under the premise of ensuring the current stability, the simpler the circuit is, the better Can lm334z with resistor and adjustable potentiometer achieve the goal? Why? Please explain the principle of constant current output of the circuit. If it is not convenient to explain, please give tips, such as telling me what concepts and principles I should understand to make this circuit
- 5. The open circuit voltage of a solar panel is 800 MV and the short circuit current is 40 ma If the battery board is connected with a resistor of 20 ohm to form a closed circuit, its terminal voltage is A.0.1V B.0.2V C.0.3V D.0.4V
- 6. According to the 12th Five Year Plan of Quanzhou City, the solar photovoltaic industry will develop by leaps and bounds. There is a solar panel with an open circuit voltage of 900mv and a short circuit current of 30mA. If the panel is connected with a resistor of 60 to form a closed circuit, its terminal voltage is () A．0.10V B．0.20V C．0.40V D．0. 60V
- 7. A solar panel, under normal illumination, has a voltage of 12V and a short-circuit current of 36ma (short-circuit current is the ammeter connected in series with the solar panel) ）A 5 ohm fixed value resistor is connected in series with the solar panel, and the voltage and current of the fixed value resistor are the reasons
- 8. There is a passive two terminal network. When u = 10V, I = 2A. It is known that the resistance network is composed of four 3 Ω resistors. How are the four resistors connected?
- 9. The open circuit voltage of an active linear two port network is 20 v. if it is connected to a five ohm resistor, a two ampere current will be generated The open circuit voltage of an active linear two port network is 20 v. if it is connected to a five ohm resistor, a two ampere current will be generated. The Thevenin equivalent circuit of the two port network can be obtained!
- 10. An active two terminal network with open circuit voltage of 12V and short circuit current of 2A has been measured_____ ?
- 11. When the voltage at both ends of the circuit remains unchanged, the resistance value increases by 2 Ω, and the current becomes 2 / 3 of the original value, what is the original resistance value
- 12. If a conductor is connected to a circuit and the voltage applied to both ends of the conductor is doubled, the resistance of the conductor and the current passing through it will be () A. The resistance and current remain unchanged. B. the resistance remains unchanged, and the current is twice the original. C. the resistance and current become twice the original. D. the resistance is reduced to half of the original, and the current is four times the original
- 13. There is such a physics problem. When the voltage at both ends of a circuit is reduced to half of the original, and the resistance is increased to twice of the original, then the electricity passing through the circuit A the original quarter B the original half C the original double D cannot be determined
- 14. 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
- 15. For example, if an electrical appliance is 380V to 220V, how is its current calculated? Is it 380V or 220V? If it is 220V to 12V?
- 16. How much current can a 4 square bv line withstand at 220 V voltage emergency How to calculate? There should be a formula
- 17. When an electric appliance is connected to a power supply after being connected in series with a 4 ohm resistance, the current of the circuit is 0.5A and the voltage at both ends of the electric appliance is 6V. The resistance of the electric appliance is Ohm and the voltage of the power supply is v
- 18. There are two resistors in parallel in the circuit, and the current flowing through the main circuit is 0.5A. If the resistance value of one resistor is increased by 10 ohm, If the resistance of the other resistor increases by 10 Ω, the current of the main circuit will decrease by 0.05A. Calculate the power supply voltage and the resistance of the two resistors!
- 19. A 4-ohm resistor is connected in series with a consumer on a 6V power supply. Now we only know that the actual power of the consumer is 2W, so the current passing through the consumer may be () A 2A B 1A C 0.5A D 0.25A how do I calculate B and C? Are they all right? Is this the question for senior high school entrance examination Big brother and big sister will come and help me. I'm in urgent need. Has anyone seen it? Tell me where it is in the middle school entrance examination
- 20. The resistance of an electrical appliance is 484 ohm, and the rated voltage is 220 v. how much work has been done by the current when the electrical appliance is connected to the circuit and works normally for 5 hours? How many kilowatt hours of electric energy is consumed?