Two electric lamps of "220 V 40 W" and "220 V 60 W" are connected in series and then connected in a 220 V circuit. The result is () A. The rated voltage of each bulb is reduced B. the actual power of each bulb is less than its rated power c. the rated power of each bulb is reduced D. the rated voltage of each bulb is less than its actual voltage

Two electric lamps of "220 V 40 W" and "220 V 60 W" are connected in series and then connected in a 220 V circuit. The result is () A. The rated voltage of each bulb is reduced B. the actual power of each bulb is less than its rated power c. the rated power of each bulb is reduced D. the rated voltage of each bulb is less than its actual voltage

According to the name plate of the bulb, the rated voltage of the two bulbs is 220 v. if they are connected in series in a 220 V circuit, their rated voltage is still 220 V and the rated power is unchanged. The actual voltage of the bulb is less than the rated voltage and the actual power is less than the rated power. Therefore, select B

A and B bulbs are marked with 220v40w and 220v60w respectively, and they are connected in series in the circuit of 220V, which actual power is higher

The actual power of 40W bulb is large. According to P = I ^ 2 * r, the current through them is the same, and the resistance of 40W bulb is large, so the actual power of 40W bulb is large

Two lamps marked with "220v40w" and "220v60w" respectively, if they are connected in series and still connected in the 220 V circuit, then
Ask for the brightness of two lights. Is a brighter or B brighter, or is it the same?
Why?

The resistance of 40W is larger and that of 60W is smaller
After being connected in series, the current is the same, the voltage with large resistance is higher, and the power is larger, so the 40W lamp is brighter, but the brightness of the two lamps is darker than that of the original single connection
If you pay attention to the observation, you will find that many old building lighting lights are directly connected with two bulbs, which saves electricity and greatly prolongs the service life of light bulbs.

How to define the unit of heat Joule is the same as that in mechanics where Joule equals 1n times m

Please understand what energy is with me now
When I have energy, I can do some things, such as lifting stones and so on. That is to say, energy is the essence of what we do. And energy will not disappear. If I lift the stone, it will have energy. If you let it go now, it will fall and make a hole in the ground. That is, you give energy to the stone, and the stone releases energy to the ground
We have summed up a rule: a moving object can work externally, that is, it has energy. (hand movement works on the stone, stone downward movement works on the ground) w = FS
Now let's explore the energy of heat, which is internal energy
For example: when boiling water, the lid of the kettle will be lifted when the water boils. The lid is static at first, and now it moves. It means that it has energy. Who gives it this energy? In fact, we all know that molecules are constantly moving, and motion has energy. Now when we heat them, molecules will move faster, This energy is provided by the combustion of firewood at the bottom of the pot. This energy is the internal energy. We can see that w = FS can also be used to calculate, but because it involves onlookers, F and s are not easy to get, so now we use a new formula: q = MC △ T
This leads to your question. Take the above example, do you think that the work done on the lid by FS and MC △ T will be the same? The answer is yes, because what? The formula q = MC △ t is created according to w = FS. It is easy to calculate the work done on the lid by w = FS, and then we know that w = q, the water quality and temperature change can be measured. Just bring w = q into the formula C, That is to say, C is a fixed value. So your problem is solved, and the results of the two formulas are the same
By the way, when you heat up in winter, when the energy of fire is transmitted to you, your skin molecules move faster, and the skin sensing cells transmit it to the brain, and you feel hot. In a word, energy transfer is all about movement, not too macro and micro
Typing is very hard, I sincerely hope to help you! Textbook is also, do not explain to students clearly