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Hi again,

Once again I am hopelessly stuck on some voltage questions.

#1) Three identical lamps are connected in parallel and then connected to a 6V battery. What is the voltage drop across each lamp?

Voltage stays constant throughout the entire parallel circuit so shouldn't each lamp continue to have a voltage of 6V?

#2) During a lab exercise you are supplied with a battery of potential difference V, two heating elements of low resistance that can be placed in water, an ammeter of negligable resistance, a voltmeter of very high resistance, wires of negligable resistance, a beaker that is well insulated and has negligible heat capacity, as well as 100g of water at 25 degrees celsius.

If the voltmeter reading holds steady at 50V and the ammeter holds steady at 5A, estimate time in seconds required to vaporize the water in the beaker. Use 4200 J/kg*degree celsius as the specific heat capacity of the water and 2.3 x 10^6 J/Kg as the heat of vaporization of the water.

I am totally lost on this question, seems more like chem one than a physics question, we haven't even done any questions like this, but it has showed up as a question in our assignment. Please help!!!!

#3) A power saw is operated by an electric motor. When first turned on these motors have very low resistance. Suppose a kitchen light and a power saw hooked up in parallel with it are both turned on. The saw , light, and lead lines have an initial total resistance of 6 ohms.

Calculate the equivalent resistance of the light-saw parallel circuit. What current flows to the light. What is the total voltage drop across the two leads to the light? What voltage remains to operate the light?

I don't know if you can figure this out without seeing the picture. I can try and describe it. There is a switch box of 120 V with two lead lines hooked up in series to a 240 ohm kitchen light which is hooked up in parallel with the power saw. The two lead lines have a resistance of .25 ohms.

Thanks again.

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# Homework Help: More Voltage

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