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The physical research method used in the experiment to explore the "factors determining the size of resistance" is______ When making conductor and resistance wire, it is mainly based on the characteristics of conductor______ It is selected according to the influence of resistance
Because the size of the resistance is related to the material, length and cross-sectional area of the conductor, the control variable method should be used in the research. When making the conductor, copper and aluminum with low resistivity should be used, while when making the resistance wire, materials with high resistivity, such as nickel chromium alloy wire, should be used; Materials
What is the experimental principle to study the factors related to the resistance of conductor
Resistance hinders the current. A small current through the circuit indicates a large resistance of the conductor
RELATED INFORMATIONS
- 1. In the experiment to explore which factors are related to the resistance of conductor
- 2. Why does the current choose the one with small resistance
- 3. The function of constant resistance in circuit It is said in the book that the constant value resistance remains unchanged, and the relationship between voltage and current is measured. Then a constant value resistance (such as 5 Ohm) is selected and measured. My question comes. ① in the circuit diagram, the constant value resistance is connected in series, and the voltmeter is connected in parallel with the constant value resistance, but how to explain the constant value resistance when measuring the current? ② the constant value resistance is connected in series to the circuit, Is the resistance in the circuit the same as the constant resistance? ③ since the resistance is the physical quantity that hinders the current, why is the value of the ammeter after the constant resistance the same as that of the ammeter placed in the constant resistance when the current passes through the constant resistance I don't have a good head
- 4. What is the difference between the ammeter connection of two circuit diagrams in the volt ampere characteristic test of nonlinear resistance?
- 5. How much current limiting resistor should this LED circuit be connected to? At present, a 5V / 4A power supply is connected to six ordinary LED lamp beads. The lamp beads need to be connected in parallel. How large is the current limiting resistance of each path?
- 6. How much resistance and power should 420 white bright LEDs be connected to 12V power supply? How many a should the power supply use? Is it OK to connect a resistor after all parallel connections? Current 20mA
- 7. The input voltage is 12V. How much current limiting resistance is needed for parallel connection of two groups of circuits with four light-emitting diodes in series? How to calculate Led 3.3.6v 20mA
- 8. What is the resistance of a 1m long data line I want to use it to calculate the power loss of the wire at 1A current
- 9. As shown in the figure, on the horizontal plane, there are two smooth metal guides without resistance, which are parallel and fixed. The spacing D is 0.5m. The right end is connected with a small bulb l with resistance of 4 Ω through a wire. There is a uniform vertical magnetic field in the rectangular area of cdfe. The length of CE is 2m. The change of magnetic induction intensity B with time t in the area of cdfe is shown in the figure. When t = 0s, a metal bar with resistance of 1 Ω acts under constant force F When the metal rod moves from ab position to ef position, the brightness of the small bulb does not change______ N. The mass of the metal bar is______ kg．
- 10. If the arc AB is 1 / 3 of the circumference, what is the resistance between ab? If point a is fixed and point B is optional on the circumference, what is the maximum value of resistance between ab?
- 11. Characteristics of resistance in series circuit and parallel circuit
- 12. Experimental steps and circuit diagram of measuring resistance by volt ampere method and safety resistance method (only one ammeter and one custom resistance are required)
- 13. The main steps of drawing circuit diagram and how to draw resistance
- 14. What does Chang'an and creative nature mean?
- 15. What is the function of resistance in the circuit of LED?
- 16. Power selection of current limiting resistor in voltage stabilizing circuit of voltage stabilizing tube Ask a friend who knows, I see a circuit board, 12VDC step-down to 5V power supply to a single-chip microcomputer, using 1n4733, but the first current limiting resistor is 330 ohm 2W, the power of this resistor I feel too large, my calculation is 7 * 7 / 330 = 0.15w or so, know the friends say your views,
- 17. What is the power flowing in a 20 ohm resistor with 5A current?
- 18. Resistance, current and voltage are the basic physical quantities in a circuit. Why not
- 19. A resistance cross-section made of conductive medium is shown in the figure. The resistivity of conductive medium is ρ, and it is made into hemispherical shell shape with inner radius a and outer radius B respectively (the shadow part in the figure). The spherical electrode with radius a and negligible resistance is embedded into the spherical center of conductive medium to become a lead-out electrode, and a layer of metal film with negligible resistance is plated on the outer spherical shell of conductive medium to become another lead-out electrode An electrode. Let the resistance value of the resistance be r. only one of the four expressions of R given below is reasonable. You may not be able to solve R, but you can judge the rationality of the following expression through certain physical analysis. According to your judgment, the reasonable expression of R should be () A. R＝ρ(b+a)2πabB. R＝ρ(b−a)2πabC. R＝ρab2π(b−a)D. R＝ρab2π(b+a)
- 20. Under the same voltage, the greater the current passing through the conductor, the smaller the resistance of the conductor. However, the resistance of the conductor has nothing to do with the voltage at both ends of the conductor and the current passing through it Two sentences are negative contradictions