Lamp Definition and 179 Threads

Hi, I am new here so please bare with me. I know a bit about electrical and Electronics but I do not recall the formula for this application...it is a long question..please help! Here it is. Six cells are connected in series to form a battery. Each cell has a rating of 1.5 volts and 1 amp...

Homework Statement what does k and n relate to? i can work them out but don't know exactly what they are. Homework Equations I=kV^n The Attempt at a Solution i think the k and n have something to do with temperature and the tungsten metal in the lamp (coefficient of resistance?)...

Question: At the bottom of a glas bath lies a mirror covered by 20cm of water.In the air,30 cm above the water there hangs a lamp.Find the distance from the mirror at which an observer looking into the water will see the image of the lamp in the mirror Relevant Formula: apparent shift...

Homework Statement A lamp hangs vertically from a cord in a descending elevator that decelerates at 1.4 m/s2. (a) If the tension in the cord is 56 N, what is the lamp's mass? (b) What is the cord's tension when the elevator ascends with an upward acceleration of 1.4 m/s2? Homework...

Question is Why does a desk lamp often has small holes near the top of the metal lampshade. How do these holes keep the lamp cool. This is what i think. Heat travels upward by air convection. Since air is a poor conductor, very little heat travels sideways. That is my reason what do u...

Hi guys I'm new here and I require some help with a project I'm working on. I'm building a lamp prototype and i need to use a potentiometer to act as a dimmer. The pot needs to fit inside a 25mm ID tube, and is connected directly to the mains. First of all is this possible? I think I have found...

Homework Statement Planning Exercise, Special Lamps may be purchased to help plants grow indoors. these lamps produce light with wave lengths comparable to natural sunlight. a manufacture wishes to check these lamps by measuring the output of the lamps at different wavelenghths. you...

Hi there, First post here guys! :biggrin: Recently i have been assigned my coursework on measuring the resistance of a filament lamp whereby an experiment was carried out by increasing the voltage through the filament lamp in intervals of 0.5 volts and measuring the current. I have since made...

Homework Statement The dynamo (generator) of a push bike is made to turn when the bicycle wheel turns. The generator provides energy to light the bicycle’s lamp. Would a cyclist coast further if the lamp connected to the generator were turned on or off? Why?Homework Equations The Attempt at a...

Homework Statement p_t=p_{20}(1+\alpha (t-20)) I have a circuit with a 3,5 V lamp that has a tungsten filament. I can provide to the circuit a variable voltage. How would I find the melting temperature of tungsten? I know p_20 and alpha and the voltage I provide. And I have an device to...

Homework Statement A person wants to push a lamp(mass 9.6 kg) across the floor a) Assuming the person pushes at a height of 60 cm above the ground and the coefficient of friction is 0.20, determine whether the lamp will slide or tip over b) Calculate the maximum height above the floor at which...

From wikipedia: A filament lamp obeys ohms law within certain limits of voltage and current so does that mean it is an ohmic device? Also from wikipedia: Sounds reasonable as well. Im inclined to believe the second quote since there are only a few values that the filament lamp will...

Hey, Check out these questions. 1. The point P lies within the angle ABC and is equidistant from AB and BC. Prove that PB bisects the ∠ABC. If point P is always equidistant from AB and BC, does that mean AB and BC are the same length? If so, that would produce congruent triangles...

Sir, The question is as follows: If excitation energy is provided by inelastic collisions between molecules, what is the temperature at which mercury vapour lamp will emit Ultra violet light of wavelength 2586 Angstrom? I tried applying Wein's displacement law(lamda * T =...

How many photons is sendt out per second from a 100 W natrium lamp, which gives a wawelenght of 589 nm(if 50% of the energi goes to the creation of light)? I think I have to use photo elektric effect, but how? Hints, anyone?

I have read somewhere that the usual lamps work on 3000 celsius so as to create light.. i am wondering why my lamp don't make my room to melt. Silly question eh?

This question is probably so easy that I'm making it too complicated but here it is: "THOMPSON'S LAMP: Consider a lamp, with a switch. Hit the switch once, it turns it on. Hit it again, it turns it off. Let us imagine there is a being with supernatural powers who likes to play with this lamp...

We have a lamp and a chronometer. The lamp is initially turned off. Then, we start running the chronometer. When it marks 30 seconds, we turn on the lamp. When the chronometer marks 45 seconds, we turn it off. When it marks 52.5, we turn it on. I think you see where am I going. The next interval...

Hi I have two probles to tackle on RLC circuits The first states that if a circuit consists of a lamp (R), variable inductance and fixed capacitor, why does the lamp glow for certain values of L. Also, you have a tuner at 100mhz, the resistance in the circuit is 15 ohms and inductance...

:cry: hi i got 2 questions here fairly confusing was wondering if i can get some help thanks 1. consider a series RLC circuit in which R is an incandescent Lamp C is some fixed capacitor and L is a variable inductance. The source is 240 V ac. explain why the lamp glows brightly for some...

A lamp is located on the ground 10 m from a building. A man 1.8 m tall walks from the light toward the building at a rate of 1.5 m s⁻¹. What is the rate at which the man's shadow on the wall is shortening when he is 3.2 m from the building ? Give your answer correct to two decimal places...

ok i asked the lamp halo question a while ago and i got a pretty insatisfactory response. i can't find the original post, but i have a theory as to why it happens. and just to clarify the original question was why is it that when you look at a street lamp from far away you see like a halo...

i was walking along somewhere and i see this street lamp. ... lol anyway so this street lamp is like ish bright, like you can look straight at it w/o hurting your eyes but its still bright. and i noticed that when you look at it, there's this like spherical shell around it, (when its dark...

ok first of all this is not a puzzler and i don't know the answer, so don't make stuff up since i won't be able to tell :). with that said, i have a a lamp that turns on when you touch it. (you could probably figure that out since i posted stuff about it before.) it is near my bed, and it is...

I do not here state that srt or it's applications would be wrong but simply I wish to bring out a faulty example. In the text box I carried about a year ago, the following "thought-experiment" and example were brought to support the mass-energy equivalence: --- Einstein's gedanken, the lamp...

What color of light would be observed if white light from an incandescent lamp were passed first through a red filter and then through a green filter.

I am using a Vacum filament lamp, i wanted to know will the temperature of the surface of the bulb will be same as room temp at 0V. the bulb is attached to a power supply. thanks

Ok, is there any solid, liquid, or gas that becomes heavier as it gets warmer and lighter as it gets colder? Like a reverse lava lamp. The little physics I know says no but I Know VERY little, you know? CJ

What is the difference between Zeno's paradox and the Thompson lamp? In PF v2.0, Ontoplasma brought this up, and I thought it was worth having a look at. Let's go through some of these "supertasks" together. http://plato.stanford.edu/entries/spacetime-supertasks