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1

How did you measure perceived brightness? If you used the visible spectrum, the increasing temperature as the power goes up will shift more of the output into the visible. If you measure total output over the whole spectrum, the relationship should be linear. The increasing resistance of the bulb should not be a problem if you truly measure power in. It ...


2

If you are looking at visual brightness, then you have to fold the wavelength dependent sensitivity of the human eye to the approximate black body spectrum of the filament into the calculation. At low power the filament will emit mostly infrared radiation, which is not visible. Even at the max. temperature of practical filaments the color temperature of the ...


0

I think that the main effect is that because humidity is increased, your sweat does not evaporate much when entering the bathroom. Since the evaporation of sweat makes you feel colder (that is what sweat is for!), you would feel warm in the bathroom. Using hot water may increase the temperature of the room as well.


0

You can calculate air velocity as v = f/A where f=volumetric air flow and A = cross-sectional area of the air passage. Also, you have m=p*f, where m=mass flow rate and p=air density. Here 1 it says that "By conservation of energy, the energy consumed in rotating the fan is the same as the energy required to deliver the air: Pfan ∝ υ"


3

Light moves at about a foot per nanosecond, or a meter every three nanoseconds. In order to capture it propagating across a room over a few frames, you would need to gather something like a billion frames per second. No consumer camera -- indeed no camera on Earth -- is capable of this. Now there have been people playing with "fempto-photography," but they ...


1

I find this all very intriguing.. Making an electromagnet requires you understand the formula shown here hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html You need to use thick wires and provide high amperage. Thicker the wire, lower the resistance and higher the current carrying capacity. You cannot keep on increasing the number of turns using ...


-2

Just get 3 steel plate and rust one of them with a solding iron and touch the tip of the 2 steel plate on the rust. This is a pnp transistor


0

In the real world you can never rid yourself of resistance in an electrical circuit. There is resistance in the connecting wires and resistance internal to the capacitor itself. So once you close the circuit and current starts moving, some of that electrical energy will be lost to heat, dissipated by resistance.


3

Comment on the question (v1): If you're confused by long-time behavior of your circuit, its behavior may be sensitive to details which are safe to neglect when describing short-time behavior. If you want a real answer, you should edit your question to include a complete circuit diagram, and perhaps a plot of your data. For example: in one of my labs I have ...


2

Short answer: yes. Longer answer: unlikely to be distinguishable from noise. Here's what happens: some photons may be reflected to various items in the camera, e.g., if the autofocus has its own sensor. The photons which follow the optical path to the CCD or CMOS detector have a certain probability of generating a photoelectron. This probability is called ...


3

The basic electric motor you described (see here and here for more complete descriptions than that provided in the question) is interesting and quite subtle to treat quantitatively, and I have not been able to find a good explanation of it on the Internet. I will provide one below. Even if the OP has moved beyond this problem, I hope others might find my ...


-1

233 atm, according to the following BBC link: http://www.bbc.com/travel/story/20150415-the-quest-for-the-perfect-pad-thai


1

Most of the masks work on the principle of adsorption. This is a surface phenomenon where particles stick to the surface of another material called adsorbent. Most commonly used material is activated charcoal. When used is a smelly environment, the particles/molecules responsible for the smell are filtered first (this happens only for larger particles) and ...



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