All Questions
Tagged with energy electricity
14
questions
3
votes
1
answer
170
views
Can a machine be powered with food energy? [closed]
Would it be possible, in principle, to create a machine that digests food in a similar way as humans do, extracts energy from the food, and stores it as electrical energy in a battery to power its own ...
- 131
-7
votes
1
answer
126
views
Is this scenario an efficient way of generating electricity?
I will try my best in order to provide information which could help you imagine the scenario. Accurate results are not compulsory.
I am generating electricity using a 5kW alternator but for the ...
- 9
0
votes
2
answers
3k
views
Role of the neutral conductor in three phase systems
In a symmetrical and balanced three phase system no current flows on the neutral conductor.
Obviously the real electric power distribution systems are not perfectly balanced, so there is a current on ...
- 3,550
33
votes
6
answers
14k
views
What is the speed of "electricity"?
In a distribution grid, what is the speed of
energy
signal
Is it strictly the same?
And how is synchronisation achieved? Is an electric grid essentially an orchestra where everyone is the chief ...
- 531
2
votes
1
answer
104
views
Assembling and Dis-assembling a Charged Capacitor
If I have an electrolytic capacitor, which is a cylindrical body in which the two plates are rolled-up with a dielectric paper in between them, of very high value (say 1F) and I charge it using a DC ...
- 1,479
0
votes
2
answers
6k
views
How to compare mAh to Watt hours?
I have a laptop with a battery described as:
3 cell Li-Ion 57Wh
I would like to know how this compares to a powerbank with 26500 mAh capacity.
How do you perform these kind of comparisons? What ...
- 101
0
votes
1
answer
795
views
What does the 20-80A rating on an energy meter mean?
On the energy meter nameplate is a current rating 20-80A, which I can assume has something to do with max current.
I'm particularly interested in the "20" part, though. What does this rating mean? I ...
- 347
-2
votes
1
answer
56
views
What is the energy consumption of incandescent bulb as compared to LEDs and CFL bulbs? [closed]
I read this on website "The electricity used over the lifetime of a single incandescent bulb costs 5 to 10 times the original purchase price of the bulb itself"
What does it mean? if the bulb is of ...
- 167
4
votes
2
answers
8k
views
In the USA, the grid transmits power at/around 60Hz. How big of a frequency deviation can the grid handle before relays trip and cause a blackout?
I understand that small frequency deviations will result in automatic load shedding or other control actions to restore system frequency, but when does a blackout occur? When the deviation exceeds + ...
- 41
0
votes
2
answers
439
views
Electric potential energy of charge relative to 2 metal plates
Let’s say I have a positive electric charge in middle of two plates, one is positively charged, the other one negatively with total intensity of electric field of 5 N/C. If the charge has 2 Coulombs, ...
- 25
0
votes
2
answers
2k
views
Calculating the annual energy consumption for a fridge
I'm looking at a spec sheet for a fridge that I'm interested in buying:http://aegelectrolux.co.za/doc/S53420CNX2/SpecificationSheet.pdf and http://aegelectrolux.co.za/cooling/bottom-freezer-fridges/...
- 103
12
votes
6
answers
24k
views
Why can I use P = I²R but not P=V²/R when calculating energy lost in a circuit?
I am working through a book of problems and am confused by the answer to this one:
A 12 V battery supplies 60 A for 2 seconds.
The total resistance of the wires in the circuit is 0.01 Ohm.
Q1. What ...
- 561
3
votes
1
answer
84
views
Generating a current with ionized water droplets (in a cloud)
Playing mind games with myself tonight; I know some of the windiest spots in the world are at the tops of mountains and often socked in the clouds. To measure meteorological phenomena at these ...
- 133
0
votes
2
answers
1k
views
Can you get electricity from your mobile phone [closed]
Does someone know if its possible to get energy from your phone (android/ios)? I want to charge a capacitor or a very little Battery and thought about the idea to get this energy from your mobile ...
- 11