Imagine a microwave oven on some kind of track such that it can reach speeds approaching c. If the microwave was switched on and shot past us at a speed so that as it traveled away from us, the relativistic doppler effect shifted the emitted microwaves into the visible spectrum - What would we...
This site was at the top of the Google results for "How efficient is a microwave oven"
I can't restart the old discussion, so I'll start a new thread.
Previous posters came up with numbers from 99% to 46%.
The Wikipedia page offers only this:
"A microwave oven converts only part of its...
I was given an oven that comprises of several cylinders that fit inside one another. The innermost cylinder is a Molybdenum oven that will hold a sample of metal. A ceramic cylinder fits over this. A tungsten wire heating element is wrapped around this cylinder. Two more ceramic cylinders fit...
My question is this: what is the average speed of atoms released from an oven at some temperature T? For example, in a Stern-Gerlach experiment, hydrogen atoms are emitted from an oven and collimated into a beam by passing them through a slit (and then sent into an inhomogenous magnetic field...
Hello, I want to build an electrical circuit powered by a temperature diffence between two unlike couple, such as copper and iron. I know a good thermocouple would be better, but I don't think I'll be able to get a hold of those materials as easily.
My current plan is to use a solar oven to...
Hey everyone. I was wondering how a magnetron in a microwave works. I understand it emits microwaves and a fan pushes them in random directions to heat up food. Thanks.
I had a phone interview. People asked me how to get the frequency of microwave oven if I do not know. I said measure it. They said, you are not allowed to use any measurement tools. Then I said, read product spec. They said, no, you do not have the spec. Finally I said I do not know. I think...
Homework Statement
I am supposed to design a control system with feedback and disturbance feed-forward, with all relevant transfer functions.
The system consists of an oven where the temperature T is controlled by an electric heater that dissipates power P_{in}. The temperature outside...
Homework Statement
Raising the temperature of 1cm^{3} of water (1 gram, water has a heat cap. of 4.2 J/g*K) using energy from a cavity filled with black body radiation. The water is to change from 299K to 300K. The radiation is initially at 450K.
If the cavity has a volume of 0.1 m^{3} how long...
Hello, I am trying to find a bearing that will allow a shaft to pass into a loop with 50bar of pressure. The basic schematic is the idea since this thread:
The water jacket protects the bearing from high temperature as the oven will heat up the fluid to a maximum of 450dC. I assume I will...
Hi, I am trying to make a Magnesium source by curling up a tungsten wire with a block of Mg inside. Then by setting electricity to the tungsten wire, the Mg is heated and you get what out? Magnesium atoms? Magnesium ions?
Thanks a lot
/Carnot
hi ,
i have studied that thing to be heated in microwave oven have water contents -due to resonance of microwave and frequency of water molecules - water molecules start oscillating with larger amplitude thus thing gets heated. But how just ceramic without any water contents get heated and how...
Hello
I am designing a solar oven that will be used to form denture moulds.
My thoughts are designing an insulated box with a doubloe pane glass double creating a green house effect.
But i would like to incorporate solar panels and a wired heated filament.
My question is what is the...
Hi all,
I am currently doing an engineering internship (still an undergrad), my field is electrical engineering so thermodynamics just confuses me!
My job has been to come up with a good Environmental Stress Screening porgram (ESS) plan, while doing this I have realized that the industrial...
Hello,
This is my first post on here, so thank you in advance for your help.
Homework Statement
I have an air tight vessel that has a volume of 1m^3. The bottom of the vessel has water in it. What internal pressure is needed inside the vessel to achieve a temperature of 45C and...
For this lab, I'm supposed to use materials that heat up but doesn't allow heat to transfer. I've used raw spaghetti noodles already but I still a few more for more trials.
So what materials are good for this lab? after heating up the material, I measure the distance between the "hot spots" so...
Is this caused by a lack of nucleation for the gas pockets to be formed or the uneven heating of the water?
A clean cup isn't proviingvery many nucleation sites and is it this combined with the even heating meanings the chance of the super heated molecules reaching these sites is reduced is...
Every time my parents move, our house has a gas stove/oven with gas burners, never electric, do very many houses have electric? What is more common, which is more modern and which is more expensive? Gas vs. Electric ?
As we know, the heating principle of microwave oven is by the vibration of water molecules inside the food. However, it is reminded that a cup of water should not be heated by the oven, otherwise, water would be overheating but not boils. Once it was stimulated, it boils.
From the...
In a hypothetical situation. If I have a vacuum oven that has an internal volume of say 2 gallons. And I want to completely dry up a solution containing around 10 mL of water (~0.5 mol).
Would it make much difference if I bring the oven to a very low absolute pressure (say 5 in Hg or 17kPa) and...
Assume that a microwave oven operates at a frequency of 1.00 * 10^11 s^-1
a)what is the wavelength of this radiation in nm?
my attempt:
wavelength=c/v so 3.00 * 10 ^8/1.00 * 10^11 s^-1= 3 * 10^19m
I would have to convert to nm correct?
so 3 * 10^19 (1 * 10^-9)= 3 * 10^10 nm??
I know it's...
Hello,
looking for a picture of black body radiation from an oven
Years ago I had found a nice illustration.
An opened hot oven was shown.
The pottery inside could hardly be seen.
This illustrated what I believe is one of most important aspect of a black body.
If is specially useful...
Hello,
I want to do a test heating a hot dog in a tube using a Magnetron from a 900W Microwave oven. Before doing the test I would like to know if there is any reasons not to mount the magnetron antenna on top of the metal tube, or on the side. (Please see attached picture)
Also, will I...
Say for instance you created an oxygen free oven, by flowing a gas other than oxygen through it and then heating up that gas. What would happen to things placed inside the oven? Objects won't be able to burn or oxidise because of the lack of oxygen, but what would happen to them?
Will objects...
i was dumbstruck :bugeye: after hearing the statement "that ice didn't melt when placed in microwave" from one of my friend, and its indeed true i checked by myself.And now I'm looking for the reason :)
Hi,
Can someone please give me some suggestions on how to use a microwave oven to determine the specific heat capacity of tap water? This is not a homework question, but an assignment and I have absolutely no idea how I can do this.This experiment will be done at home, so please no immersion...
I would like to put a cup of water in microwave and measure the temperature of the water as it rises with time in the microwave. Obviously electronic equipment will be fried in a microwave, but would it be possible to put a thermocouple in the water with its lead coming out of the microwave...
Metal inside a microwave oven --> ice?
When I was younger, I placed water inside a tin pan and placed it inside a microwave. I tuned it on, sparks went everywhere and I quickly turned it off. I took the pan out and it was solid ice. How?
A while ago I read an article in New Scientist that...
I recently purchased a new microwave oven, and there's a metal rack in it. The salesmen informed me that it shouldn't cause any problems as long as it didn't touch the sides; however, he was unable to tell me why this is. I have a basic understanding of how microwaves(as in the radiation not the...
Homework Statement
Microwave oven I. The glass window isn't important to the microwave oven's operation, but the metal grid associated with that window certainly is. The grid forms the sixth side of the metal box that traps the microwaves so they cook food effectively. What is the approximate...
If one had a microwave oven transformer (MOT) from a microwave that was said to be 1200W, and the transformer itself had an output of 2300V, would that mean that the current would be:
Power = Current * Voltage
1200W = Current * 2300V
Current = 0.52A
The reason I ask is because: I'm...
just wondering if i put oil in a microwave oven will the oil get heated and why?
i know polar substances will be heated but I am not sure if the same thing will happen to non-polar substance like oil
I hope I am posting this on the right section...
In my Environmental Science Class, we are to design and build a solar oven(without using solar panels!). We will be baking a cookie.
Me, being a "mathematician", remembered something about a parabola, that if light ray hits anywhere on...
Homework Statement
A turkey is put in an oven maintained at a constant temperature of 210^{\circ}C. At time t=30 minutes, the turkey is 135^{\circ}C and is increasing at a rate of 1.8^{\circ}C/minute. The model for the turkey's temperature is
T(t) = 210 - ae^{-bt}
Find the values of a...
I was curious about microwave ovens and how they work and in particular about the microwave radiation they emit and the halflife of this radiation. My layman's understanding is that microwave ovens use a 2.43GHZ emf to heat up water inside food items by attenuating 1 or more? of the few...
Homework Statement
The temperature in an electric oven is 158°C. The temperature at the outer surface in the kitchen is 51°C. The oven (surface area = 1.8 m2) is insulated with material that has a thickness of 0.023 m and a thermal conductivity of 0.045 J/(s·m·°C).
(a) How much energy...
Hi, can anyone please help with my project of building a portable miniture Gas (butane)powered oven. Approx a 1" cube or ball shape? Needs to be able to raise temp quickly, and hold even oven temp of approx. 200Deg. Celsius...
Thanks,
Richard
My daughter claims that when she runs our microwave oven, it disables her laptop computer connection to our wireless router. What might cause that? Will we be sterlizied?? (just joking...I think!)
One possibility is that when the microwave oven draws power sparking from a loose 120 wall plug...
Homework Statement
Hey guys, I have a homework problem in my electromagnetism class that's got me a little stumped. I'm supposed to measure the interior dimensions of my microwave oven and use that to calculate the 5 lowest frequencies at which I can sustain a mode in which I have standing...
Hello, I've been watching some videos on youtube of people putting a lit flame into a microwave oven. After a few seconds the flame bursts into a bright ball of plasma, why is this?
Is there anywhere online that I can research the science that causes this...
Electron "oven" In S-G Experiment
This isn't so much a homework problem but I guess it fits more here then in the other areas of the forum.
Whilst we were deriving and expression for the deflection of particles in the Stern-Gerlach experiment, the lecturer stated that the particles emerge...
http://www.headcook.co.uk/lodge-logic-dutch-oven-1025-p-2069.html?source=webgains&siteid=7963
Is this a good one? it looks way to big for cooking for one, but if i cook a batch of chili may be it will last all week?
I need to construct an oven thermometer out of scratch using any materials that are purchasable. Our restrictions are:
- No mercury
- The product must be able to read from 250 degrees fahrenheit to 500.
- MUST FIT IN THE OVEN PLZ.
thank you
A student takes 0.45kg of ice. The ice is initally at -23'C. She heats the sample in an oven until the temp is 134'C.
a). What is the Q needed to heat the ice to its melting point?
b). What is the Q needed to change the solid ice into liquid water?
c). What is the Q needed to heat the liquid...
Has anyone out there actually tried the kitchen experiment of placing a continuous line of meltable food (i.e. marshmellows/chocholate/cheese etc.) across the bottom of a microwave oven in hopes of finding the antinodes of a standing wave by looking for regions that melt while the rest of the...