Physical electricity: measuring the resistance of a small bulb, Now you don't have an ammeter. You only have a voltmeter, a sliding rheostat, a 10 ohm quantitative resistor, a 6V power supply, a switch and several wires. At this time, you can't measure the resistance of a small bulb by volt ampere method. What's the resistance of a small bulb? You need a circuit diagram,

Physical electricity: measuring the resistance of a small bulb, Now you don't have an ammeter. You only have a voltmeter, a sliding rheostat, a 10 ohm quantitative resistor, a 6V power supply, a switch and several wires. At this time, you can't measure the resistance of a small bulb by volt ampere method. What's the resistance of a small bulb? You need a circuit diagram,

This circuit diagram is not fixed. Although there is no way to measure the current directly, you can use a voltmeter to measure the voltage at both ends of the constant resistance, and then use Ohm's law to calculate the current. That is to say, the voltmeter should measure the voltage twice, one for the constant resistance and the other for the lamp

What voltage, current and resistance does the bulb light up normally

Description of normal lighting of the bulb: the power supply voltage of the bulb is the rated voltage U of the bulb. At this time, the current on the bulb is the rated current I of the bulb, and the rated power P of the bulb is u * I. the resistance R of the bulb is U / I

The resistance of a bulb is 40 Ω and the current is 0.5A in normal operation
The resistance of a bulb is 40 Ω, and the current in normal operation is 0.5A. To connect it to the voltage of 220 V, the resistance in series should be Ω
One more question
When two bulbs marked with "6V 3W" and "6V 6W" are connected in series in a certain circuit, only one bulb can light normally, and there is no abnormal phenomenon in the circuit, what is the voltage at both ends of the circuit?

Total resistance = u / I = 220 / 0.5 = 440 Ω, and the resistance in series = total resistance - bulb resistance = 440 - 40 = 400 Ω. You can't ask this question. When two different resistances are in series, the voltage shared by the large resistance is also high. According to the resistance = voltage ^ 2 / power, there is "6V 3W" resistance R1 =

Is a light bulb a resistive element? If so, how to draw the element symbol in the circuit diagram? Is it a light bulb or a resistor? Similarly, I think the wire is a resistor
It must be a resistor. Why only draw a straight line in the circuit diagram instead of the symbol of the resistor element~

In the circuit diagram, the symbol of the light bulb is distinguished from the symbol of the resistance. This is because: 1. The light bulb will emit light, which is very intuitive and obvious when it is working; when the resistance is working, it is not easy to directly observe with naked eyes; 2. As a resistance, the resistance of the light bulb is greatly affected by the temperature, and the resistance will be tens of times different when it is working and not working