Quiz on capacitors

[ICIT2LOL]

Try this one for size we are always talking about then m and without cheating see wat you get .

Me ? 10/10 of course
HowStuffWorks "Capacitor Quiz"

 

[Ranger4]

10/10 here as well, but that doesn't say much as it's a fairly basic test.

 

[Windows Sniper]

9/10,

Considering I learnt most of this from random places over my short years, i'm fairly suprised at this.

 

[ICIT2LOL]

10/10 here as well, but that doesn't say much as it's a fairly basic test.

Yep basic it might be mate and I would have liked to have seen some of different types mentioned , and mind you it is surprising how many would not know anything at all about these what I consider are one of the most trouble prone components of any system.

 

[Lady Fitzgerald]

I take exception to two of the questions. One, air capacitors are no longer used in tuned circuits in radios and haven't been in years. Two, lightning is an electrical discharge, not an example of a capacitor.

 

[ICIT2LOL]

I take exception to two of the questions. One, air capacitors are no longer used in tuned circuits in radios and haven't been in years. Two, lightning is an electrical discharge, not an example of a capacitor.

Yep I know about the air ones but I wonder how many don't even know they existed as for the lightning well technically I suppose the cloud/s are the capacitor in a sense.

having said that there are many enthusiasts that still work with the older type radio sets that sue those type of caps.

In reality one can act as a capacitor oneself and I think and I stand to be corrected that a lot of touch screens work on the principle that body mass alters the capacitance in the area touched as I know I built some stud finding device years ago that used that principle.

 

[Lady Fitzgerald]

I haven't seen an air gap variable capacitor in over 20 years (and what I saw then was really ancient). I have seen air gap capacitors on radio antennas, especially for high power transmitting, since then.

 

[strollin]

I take exception to two of the questions. One, air capacitors are no longer used in tuned circuits in radios and haven't been in years. Two, lightning is an electrical discharge, not an example of a capacitor.

9/10 for me. But, I also take exception to the lightning answer. I actually believe snow is closer to being analogous to a capacitor than lightning. I liken snow building during a storm as the capacitor charging, then the snow melting as the capacitor discharging.

The quiz was actually less than basic, most of the questions were actually irrelevant.

 

[Lady Fitzgerald]

I take exception to two of the questions. One, air capacitors are no longer used in tuned circuits in radios and haven't been in years. Two, lightning is an electrical discharge, not an example of a capacitor.

9/10 for me. But, I also take exception to the lightning answer. I actually believe snow is closer to being analogous to a capacitor than lightning. I liken snow building during a storm as the capacitor charging, then the snow melting as the capacitor discharging.

The quiz was actually less than basic, most of the questions were actually irrelevant.

Snow was also my answer.

 

[ICIT2LOL]

I haven't seen an air gap variable capacitor in over 20 years (and what I saw then was really ancient). I have seen air gap capacitors on radio antennas, especially for high power transmitting, since then.

Hum have a few old sets at home my son and I used to mess around with - just love those vacuum tubes

 

[Lady Fitzgerald]

I haven't seen an air gap variable capacitor in over 20 years (and what I saw then was really ancient). I have seen air gap capacitors on radio antennas, especially for high power transmitting, since then.

Hum have a few old sets at home my son and I used to mess around with - just love those vacuum tubes

Yeah, the glow from them was pretty awesome (and pretty). I loved the old mercury vapor rectifiers; those were really cool!

 

[Ranger4]

10/10 here as well, but that doesn't say much as it's a fairly basic test.

Yep basic it might be mate and I would have liked to have seen some of different types mentioned , and mind you it is surprising how many would not know anything at all about these what I consider are one of the most trouble prone components of any system.

I do agree with you about capacitors as being one of the most troublesome parts of a circuit & have experienced a few exploding while in actual use & this results in the foil being reduced to something like confetti & being blasted all around the interior of the unit. Hell of a problem to clean up.

I was a bit surprised that some selected snow instead of lightning in that question, as snow is actually frozen rain.

 

[Layback Bear]

Well I didn't answer the air capacitor as the test required.

Lightning is the results of a capacitor discharge, example clouds being the capacitor.

What the test didn't get to is a capacitor can hold huge amounts of volts/amps for a very long time and if discharge incorrectly can kill you.
That's one of the first things I was taught in Radio A School in the Navy.
The Navy had shipyard workers get killed working on 20 year old ships with discharging capacitor not in the correct way.

The Navy didn't want us dead and useless after spending all the time and money on training us to be Radiomen.
That is why I give warnings on not going into a power supply.

 

[Lady Fitzgerald]

...I was a bit surprised that some selected snow instead of lightning in that question, as snow is actually frozen rain.

Actually, frozen rain is sleet. Snow is crystalized water.

 

[Lady Fitzgerald]

...That is why I give warnings on not going into a power supply.

Same here. I worked in the electric power industry for 32 years. We worked with capacitor banks often physically big as small automobiles. You could weld ships with the power stored in those. They were shipped from the vendors with the terminals shunted to ground because they could pick up enough induced current (commonly referred to as static although that wasn't what it was) to easily kill someone just from moving them around. When removed from service, they had to be discharged and have the shunts reinstalled. Not reinstalling the shunts or removing them prematurely was a firing offense.

The sneakiest "capacitors" that knocked me on my backside more than once when I was a kid were TV picture tubes. Those could hold a high voltage charge if the flyback coil was bad and didn't let them discharge. Grabbing the high voltage lead to pull it off while the tube was holding a charge would give quite a jolt that ranged from extremely annoying to one that could easily kill. I used to rummage around behind a TV repair shop (remember those?) on the way home from school for old TV and radio chassis to salvage components from. I quickly learned to slip an old screwdriver under the boot where the flyback lead connected to the picture tube and shunt it to ground before messing with anything else.

 

[strollin]

... I was a bit surprised that some selected snow instead of lightning in that question, as snow is actually frozen rain.

Whether snow is frozen rain or crystalized water is irrelevant for the purposes of an analogy. For instance, when I went to electronics school, water pipes and plumbing were often used as analogies for all sorts of electronics theory. Water pressure was analogous to voltage while water flow was analogous to current.

 

[derekimo]

Well since the question was "Which of these is a natural example of a Capacitor?" I think Lightning fits better than snow, I understand your analogy and the use of water terms when being taught about electrical theory.

While snow can be used as an analogy for the charge/discharge process, lightning is more of an example of a capacitor, clouds being one plate, the ground being the other, and the air in between the dielectric with lightning the discharge.

Besides all that, they had to get their info somewhere and it was probably from someplace like this,

Molecular Expressions: Electricity and Magnetism - Interactive Java Tutorials: Lightning: A Natural Capacitor

Clouds and the ground can act in unison to mimic a huge natural capacitor. The process of evaporation and condensation of atmospheric water within clouds causes water droplets to collide with dust, ionizing radiation, and each other.

These collisions cause electrons to be knocked off the particles creating a charge separation in the clouds. Negative electrical charges accumulate at the base of clouds. The base of the clouds can be compared to a negative plate of a capacitor. These charges induce positive charges to accumulate in the ground, comparable to the positive plate of a capacitor. The air between the clouds and ground becomes the dielectric of this natural capacitor. The electrostatic field between the clouds and the ground can produce ions and free electrons in the air. Eventually the difference in potential between the clouds and the ground can become so great that the air dielectric begins to break down. The ions and free electrons provide the necessary path that short-circuits this natural capacitor, initiating a flash of lightning.

 

[IownAmoneyPit]

Don't know how I did it as it was a complete guess on the last question & a couple of others.

 

[Lady Fitzgerald]

Well since the question was "Which of these is a natural example of a Capacitor?" I think Lightning fits better than snow, I understand your analogy and the use of water terms when being taught about electrical theory.

While snow can be used as an analogy for the charge/discharge process, lightning is more of an example of a capacitor, clouds being one plate, the ground being the other, and the air in between the dielectric with lightning the discharge.

Besides all that, they had to get their info somewhere and it was probably from someplace like this,

Molecular Expressions: Electricity and Magnetism - Interactive Java Tutorials: Lightning: A Natural Capacitor

Clouds and the ground can act in unison to mimic a huge natural capacitor. The process of evaporation and condensation of atmospheric water within clouds causes water droplets to collide with dust, ionizing radiation, and each other.

These collisions cause electrons to be knocked off the particles creating a charge separation in the clouds. Negative electrical charges accumulate at the base of clouds. The base of the clouds can be compared to a negative plate of a capacitor. These charges induce positive charges to accumulate in the ground, comparable to the positive plate of a capacitor. The air between the clouds and ground becomes the dielectric of this natural capacitor. The electrostatic field between the clouds and the ground can produce ions and free electrons in the air. Eventually the difference in potential between the clouds and the ground can become so great that the air dielectric begins to break down. The ions and free electrons provide the necessary path that short-circuits this natural capacitor, initiating a flash of lightning.

Truth be told, I didn't feel any of the choices were applicable so I just picked snow since it is a heat insulator and could have been analogous to the dielectric (aka insulator) of a capacitor. Lighting is a discharge, not a capacitor itself. It was a poorly thought out question.

 

[A Guy]

10/10 But I rarely work with lightning

A Guy