Reads the voltage and current tables. For example, by drawing circuits, the cause of the failure in the circuits。
• 3. The light is found when the last lead is connected to the circuit。
· 5. Closed switches, no indication of current table, light bulbs and voltage. The switch was not disconnected while connecting the circuit and the sliders were not moved to the maximum barrier。
Breaks of circuits occur outside the voltage watch, short circuits occur within the voltage table, short circuits outside the current table, short circuits within the current meter or inside the voltage table。
• review experiment i: exploring the law of om。
#1, visualize other electrical resistance, move sliding transformers, and record the current gauges。
→2, switch to other electrical resistance, move-sliding transformer, and record the current table markers: based on experimental data from two tables, the analysis leads to conclusions。
Table 1: look at the relationship between one and the u。
Further analysis from above shows that currents, voltages, currents in the conductor are proportional to the voltage at both ends of the conductor and inversely to the resistance of the conductor. That's the famous om law。
→ when connected to a circuit, the switch shall be disconnected。
→(2) slide transformer shall be moved to the maximum barrier。
The functions of sliding transformers in experiments are:
When investigating the relationship between currents and voltage, ming tested it with a switch and found that the current gauge pointer exceeded the quantum range, which would have occurred if all parts of the circuit had been intact. If the pointer is found to be left, the reason for this is:
→2, if he wanted to explore the connection between currents and resistance, he used 102 changes in the experiment, thus maintaining consistency. This is due to the fact that the current meter is too small and this is due to the fact that the current meter is inversely negative。
• experiment ii: vacat for electrical resistance。
→1, measured electrical resistance。
→2, light bulb electrical resistance measurement: analysis of experimental findings based on experimental data from two tables。
→1, measured electrical resistance。
Changes in electrical resistance currents and voltage of small light bulbs. The functions of sliding transformers in the experiment are as follows:
→1. In measuring electrical resistance: alter the voltage and current of electrical resistance。
→3. When measuring light bulb resistance: change the voltage and current of the light bulb. This is shown as a chart of the electrical circuits measuring resistance to a small 2. 5v light bulb。
→1, fill in the voltage meter current table symbol in the circle in figure a. Indices are (0. 3)a and the electrical resistance of small light bulbs is 8. 3 om when the light is normal。
Using this experiment, the rated power of the light bulb can also be measured at 5 om。
As shown, the circuit for measuring electrical resistance to small light bulbs is complete (2. 5 v electrical resistance is marked on the light bulb at approximately 10 euros)。
→1 and kogaku want to use van to measure an electrical blockage r, which has been connected to some of the circuits, as shown in the chart, please help him complete:
(1) the electrical circuit is supplemented by a pen line instead of a guide. The current in the circuit was 0. 3a and the electrical resistance was 12. Small current values, resulting in an average of resistance, are designed to reduce errors and bring the average closer to real values。
Experiment iii: measurement of light bulb power. Data tables on the power of small bulbs:
→1, a student needs to measure the rated power of a small light bulb with a rated voltage of 3. 8v and design the circuits as shown in the chart
→1, during the connection to the physical circuit, the switch should be in a state of disconnection, as the voltage gauge will be larger when the slide p against short-circuit sliders is prevented。
→(2) the current expression is shown as a chart, when the current size of 5 in the circuit is to prevent excessive currents and burn down circuits by connecting to circuits and moving sliders。
(2) when the circuit is connected, close the switch and move right。
In the "measuring the power of small light bulbs" experiment, the power voltage was 6v and the rated voltage of small light bulb l was 2. 5v。
(i) please use a pen line instead of a guide, and complete the circuit. The current meter will be larger。
→(3) closed switch s. Found that the light bulb was not lighted, regardless of how the slide transformer was regulated. And the voltage table has an indication and current expression is always zero. The cause of the malfunction。
(4) in the course of the experiment, if the light bulb is inadvertently short-circuited, it is because the light fuse is broken or the lamp has poor contact with the pole. The method of summarizing patterns based on experimental phenomena and data。
Example 1: on the basis of the following tips of experimental operating graphics, a thermometer reading is found to be different, using the physical knowledge we have learned, indicating that when electrical currents are the same as when they go through, the electrical resistance of the electrical conductor is greater, resulting in the recording of their respective experimental data in the same table. Each of the three experimental devices shown below is the pattern of the hint and its application。
The →prop map experiment revealed that the following blanks were completed based on observations made in b, c and d. By observing the differences in the number of electro-magnets attracted to large needles, it can be judged that the larger the passing electrical currents, by comparing d with d medium- and b electro-magnetics, the electromagnetics having the same shape, the power voltage remains the same through the same caseline, as shown in the chart, and when the switch is closed, the electrical voltage may be due to the following reasons。
