PV Gap

Lillian Said:

Is this a well-written, helpful review?

We Answered:

Didn't read past the first line because it was pretty bad.

I hadn’t had to wait long??????

COOMEEE ONN!!!

Also it is waaay too long. Try to be concise. No one is going to read that. A couple of well chosen lines would suffice.

Jane Said:

Is it possible that the universe is nothing more of a braincell of another life form?

We Answered:

There is a time in everyone's life when they have this idea. Although it seems to make sense at first, the comparrison quickly falls apart.

On a large scalr structure, it doesn't appear to work. If we want to call galaxies nerve celles, or even parts of nerve cells, what's linking them? Nerve celles are linked to one another and carry out processes together, while the galaxies of the universe are completely seperate entities.

Monica Said:

Could a RC Airplane powered by batteries or fuel carry a payload of 84 grams 30 miles, airdrop it and return?

We Answered:

yes it could

Crystal Said:

Which settings to use for multimeter? Scanned diagrams included.?

We Answered:

There are several sources of the variability you have described.

First of all, your conclusions about the roundup of significant digits to fit the readout is most likely correct.

Second, remember that each scale setting (20 mA, 200 mA) indicates the maximum value of the range you will be able to measure. This means that a 40 mA current will max ('peg') the meter set on "20 mA", but give a reasonable reading set on "200 mA".

But I am concerned about the the overall stability of the measurements. It is very difficult to get stable readings with those pin-type probes, no matter how hard you press down. The pin area in contact with your solar cell circuit will vary, and impose a different series resistance each time, so the current (and resistance) will vary.

This could easily be the case when you measure different resistances on the two different scale settings. If you clip your pin leads to your circuit, and don't move anything around, then the resistance between the leads should remain the same, within the number of digits, when you switch the range of the meter between 20 and 200 KOhms. Just the least significant digit should be dropped off during the upswitch. The fact that it changes on simply changing the scale suggests that the leads are not stably connected to the circuit.

One solution is to slip small aligator clips onto the pins and use the clips to squeeze onto the circuit locations between which you are measuring the current.

This instability will also explain your variable current readings. The 178 you read on the "2000 uA" range setting suggests that this was the read with the pins pressed the most tightly against the solar cell. Some variability in current could also result from differences in illumination. Again, you want your solar cells immobilized or otherwise fixtured and pointed at the light source and not move around.

The reading of 12.345 on a range of 20 mA means 12.345 milliamperes. The m's mean milli and the u's mean micro.

Toni Said:

QUICK!! I need this answering within the next half an hour...?

We Answered:

Solar cells use light (photons) to generate power (voltage). It naturally follows that this process be called the photovoltaic effect.

When solar radiation is absorbed by solar cells, photons from the sunlight enter the cell and bump into electrons and displace them. At this point, special electrical semi-conductors within the solar cell capture these electrons and complete a circuit between the top (negative charge) and bottom (positive charge) of the solar cell.

The process may vary slightly depending on the various types of solar cell, but the basics remain the same as shown in the diagram on the website

a solar panel/module is a group of solar cells. they work the same way.

Carmen Said:

what happens if you take a picture of a solar eclipse with your cell phone?

We Answered:

You would get a big bright spot in the picture a Lunar Eclipse is different your phone will work just fine go for it the Lunar eclipse Tonight will not happen again for another 450 years.