Tagged Questions
-1
votes
0answers
24 views
Increasing Amps [closed]
I am not sure if this is the place to post this, but both physists and electricians should be able to help here, so I am going to cross post with DIY (sorry if this really annoys people - I know it ...
1
vote
2answers
46 views
Light bulbs, Wattage meaning? [closed]
Light bulbs, Wattage meaning?
Two incandescent bulbs (120 V, 25 Watt) and (120 V, 500 Watt) connected to the same batteries.
Which one shines brighter? And why?
3
votes
1answer
101 views
Is it possible to get energy from electrical wire using induction?
Pardon me if this is a stupid question but my physics courses are from a long long time ago and I was a teenager back then. ;)
Electricity in a wire generates electromagnetism, right?
Would it be ...
0
votes
2answers
550 views
Confusion about P=VI and V=IR
If we look at $P=VI$, we see that if the current doubles then the potential difference is halved
but this doesn't seem to make sense according to $V=IR$. If we look at that equation, since the ...
1
vote
3answers
2k views
Average power dissipated by a resistor on AC current
So let's say we have an AC current of 120 V at 60 Hz. Then i's waveform would be
$$f(t) = 120 \sqrt{2} \cos(2 \pi 60 t)$$ Or rather the amplitude times $\sqrt{2}$ times $\cos(2 \pi ...
2
votes
2answers
155 views
Can wireless power transfer harm organic life by anyway?
Now, humanity can beam 50-60 watts power through 10 centimeter-thick concrete block. Can such wireless power transfer harm us by anyways?
0
votes
1answer
92 views
Do you think it’s possible to make a power plant of the described kind?
We are working on a science project and try to engineer a power plant of a new kind. It is called Air HES (air hydroelectric station). The idea is described on our website.
Do you think it is ...
1
vote
2answers
296 views
Calculate power $P=V \times I$
I have an adapter which mentions like this...
Input: 100-240V~1.8A
50-60hZ
So how much power does it really consume?
I just knew ...
0
votes
2answers
310 views
How can you measure battery output to see if the wattage is accurate? [closed]
When you have a battery and it shows you the milliamperehours and volts. You can use those to calculate the wattage. How can you test the battery to see if its wattage is accurate or if the company ...
1
vote
5answers
291 views
How do electrical devices suck electricity?
If the electric potential is 220V and some device needs 1500watts then how does it suck exactly that amount of electrical energy from outlet?
0
votes
3answers
426 views
How can AC source with different voltage provide same power
As some of us maybe aware, USA mains connection is 110 V while those in Asian countries are 220 V. How is it still possible for the Adapter to provide the necessary power to the device, say a laptop, ...
0
votes
3answers
9k views
Charging 12V 150Ah battery
I want to charge a 12V battery of 150Ah with a solar panel. The solar panel specs is
12V, 25 Watt.
Can anyone please provide me how to calculate that how much time it will take to charge the battery? ...
2
votes
2answers
902 views
Total power consumption of electric device
For some electric devices, like a fan or air conditioner, I read about their power consumption in watts on their specification guide.
Does it tell about the power at normal or full speed? or Does the ...
1
vote
2answers
1k views
How do I calculate the power consumed by a lightbulb?
I'm studying a lightbulb and its variable resistance, given by the expression:
$R(T) = Ro[1 + α(T-T_0)]$, where $R_0$ is the resistance of the lamp at $T_0$.
In this case, $R$ is not given by Ohm's ...
2
votes
2answers
314 views
Why doesn't a phone charge faster, rather than slower when it is in use
In Physics class, we were building parallel circuits, and as more lights were attached in parallel, they got brighter (as more power was being provided to the lights, and the resistance decreases). ...
8
votes
3answers
2k views
Why do power lines sag when they are heated up?
I was reading some information about the 2003 power blackout in the Northeastern US.
Beginning early in the afternoon of August 14, 2003 big transmission lines began to fail in First Energy's ...
2
votes
4answers
781 views
Do Alkaline batteries, NiMH, rechargeable alkaline, Lithium AA, all have similar MAX POWER?
So in physics, one smart teacher told me,
V = IR
or
I = V / R
but it is not always true, because ...
