# Tagged Questions

The time rate of change of energy

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### How feasible is it to power your home with a bicycle? [on hold]

This article claims "60 Minutes On This Bicycle Can Power Your Home For 24 Hours!" How feasible is this claim? Sounds great - but the skeptic in me says "yeah, right." Hope this is an acceptable ...
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### Do we use rms values or peak value for calculating power of a transformer?

Do we use rms values or peak value for calculating power of a transformer? I have an A levels exam tomorrow and I wasn't able to find any kind of explanation in the book.
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### High Voltage Powerlines - clarification of energy loss

I've been having a bit of trouble understanding the High-Voltage powerlines. If I was sending power from $A \rightarrow B$, we have: Ohm's law $V = IR$ Power lost in the form of heat $P = I^2 R$ ...
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### Power dissipation in AC RC circuit [closed]

Can anyone help me with this question? A 20 A peak-to-peak 60 Hz current passes through a 0.01 µF capacitor which is in series with a 33 Ω resistor. What is the power dissipation? I have ...
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### Relationship among heat generated, power, current and voltage

Can you help me understand the relationship between current, voltage and heat generated? I tried two sets of heated gloves. One uses a battery which generates 7.4 volts x 2 amperes (14.8 watts of ...
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### Opposing currents in a Ciruit

If I have two currents flowing in opposite directions in a wire where both currents are equal magnitude and their is a bulb on the same wire does the bulb light up at all or is it bright/dim ?
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### In 3 three power system, can damage occurs from incorrectly connected phases?

A three phase generator, no grid involved, phase 1 connected to phase 3 on the load, and phase connected to phase 1 on load, what is going to happen?
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### What is the power given by centripetal force?(in circular motion)

A particle of mass $m$ is moving in a circular path of constant radius such that the centripetal acceleration is varying with time as $a_c = k^2rt^2$ where $k$ is constant. The power given to the ...
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### How much power can nuclear power plants produce? [closed]

I looked at the power plants with the highest capacity and hydroelectric plants seem to dominate the list. Surely nuclear plants could be far more powerful? I assume they are limited because of ...
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### What is the relation between power and photocurrent? [closed]

Question: A clean lithium surface is illuminated by 1.0 mW of light of wavelength 400 nm. The ejected photoelectrons, which have a maximum kinetic energy of 0.70eV, produce a photocurrent of 30 µA. ...
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### Voltage and reactive power

Why are reactive power and voltage related? When the control system of a generator increases/decreases the current of the rotor, voltage and reactive power are increased/decreased.What is the relation ...
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### If energy of a wave is proportional to frequency, why are higher-powered lightbulbs brighter?

E = hf. Got it. P = dE/dt, right? Not seeing an amplitude anywhere in the formula, so shouldn't the power rating on the lightbulb only be driven by the color? Is it a problem with the way the ...
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### power in an ac circuit - difference between in series and parallel

In AC-circuits, we have different kinds of power: active power $P$, reactive power $Q$ and apparent power $|S|$. Let's say we have a circuit with a resistor $R$ and an inductor $L$. My understanding ...