Monday

April 20, 2015

April 20, 2015

Number of results: 129,793

**College Physics**

How much would you have to raise the temperature of a copper wire (originally at 20 ∘ C) to increase its resistance by 30% ?
*September 17, 2013 by TaNay*

**Physics**

I'm trying to determine the specific heat of copper by experiment and I have a question about the change in temperature of the copper. If I take the copper out of boiling water at 100 deg. C and place it in water at 10 degrees C, the temp. of the water increases to 14 deg. Is ...
*May 7, 2009 by Brigid*

**physics**

To what temperature must you raise a copper wire, originally at 20.0C, to double its resistance, neglecting any changes in dimensions? (Does this happen in household wiring under ordinary circumstances?)
*September 13, 2014 by Jane*

**physics**

To what temperature must you raise a copper wire, originally at 20.0C, to double its resistance, neglecting any changes in dimensions? (Does this happen in household wiring under ordinary circumstances?)
*September 14, 2014 by Linda*

**Physics**

A copper wire has a resistance of 24 Ω at 20C. An aluminum wire has three times the length and twice the radius of the copper wire. The resistivity of copper is 0.6 times that of aluminum. Both Al and Cu have temperature coefficients of resistivity of 0.004C1. What is ...
*November 17, 2010 by Trace*

**physics**

A copper wire has a resistance of 0.425 at 20.0C, and an iron wire has a resistance of 0.455 at the same temperature. At what temperature are their resistances equal?
*September 15, 2013 by Justin*

**Physics **

Two cylindrical copper wires have the same mass and are at the same temperature. Wire A is twice as long as wire B. The resistance of wire A is related to that of wire B by : a) RA = RB/4 b) RA = RB/2 c) RA = RB d) RA = 2RB e) RA = 4RB
*September 24, 2014 by Anonymous *

**Physics **

Two cylindrical copper wires have the same mass and are at the same temperature. Wire A is twice as long as wire B. The resistance of wire A is related to that of wire B by a) RA = RB/4 b) RA = RB/2 c) RA = RB d) RA = 2RB e) RA = 4RB
*September 24, 2014 by Anonymous*

**physics**

Consider two copper wires with the same cross-sectional area. Wire A is twice as long as wire B. How do the resistivities and resistances of the two wires compare? CHECK ALL THAT APPLY Wire A and wire B have the same resistance. Wire A has twice the resistivity of wire B. Wire...
*February 7, 2014 by Anonymous*

**physics**

A silver wire has resistance of 2.1ohms at 27.8 degree celsius and resistance of 2.8ohms at 98 degree celsius. Determine the temperature coefficient of resistance of silver wire and its resistance at zero deg.
*March 16, 2010 by Edwin*

**Physics**

Two wires with the same resistance have the same diameter but different lengths. If wire 1 has length L1 and wire 2 has length L2, how do L1 and L2 compare if wire 1 is made from copper and wire 2 is made from aluminum? The resistivity of copper is 1.7 10-5Ωm and the ...
*October 15, 2010 by Max*

**physics**

By what factor is the resistance of a copper wire changed when its temperature is increased from 20C to 120C? (the temperature coefficient of resistivity for copper = 3.9 10‑3/C)
*February 7, 2011 by Anonymous*

**physics**

Suppose that you wish to fabricate a uniform wire out of 0.900 g of copper. Assume the wire has a resistance R = 0.500 , and all of the copper is used. (a) What will be the length of the wire? (m) (b) What will be the diameter of the wire? (m)
*September 17, 2010 by lynette*

**physics**

A wire has a resistance of 27.2 ohms. It is melted down, and from the same volume of metal a new wire is made that is 3 times longer than the original wire. What is the resistance of the new wire? Resistance and length of wire are proportional, but what I am unsure of is if ...
*July 25, 2012 by Lauren*

**Roper**

You've made the finals of the Science Olympics! As one of your tasks, you're given 1.1 g of copper and asked to make a wire, using all the metal, with a resistance of 2.0 (ohms). Copper has a density of 8900 kg/m^3. What length will you choose for your wire? What diameter will...
*March 24, 2011 by Daniela*

**Physics**

(1) 45 micro coulombs of charge is passed through a wire in 35 seconds. How many electrons does this represent? What is the current in the wire? (2) A piece of copper wire has a resistance of 5 Ohms at 20 degrees celsius. If another piece of copper wire at 0 degrees celsius is...
*May 4, 2009 by Bob*

**Physics**

Suppose that you wish to fabricate a uniform wire out of 1 g of copper. (Resistivity = 1.72*10^-8 Ohm-m, density = 8.94*10^3kg/m^3). If the wire is to have a resistance of R = 0.5 ohm and all of the copper is to be used, how long is the wire? a. 1765 m b. 1816 m c. 1.8 m d. 0....
*March 1, 2013 by John*

**Physics**

You have a piece of copper with a volume of 2 cm3, and wish to form a wire having a resistance of 0.15 . How long should the wire be if the resistivity of copper is 1.72 ~ 10-8 . m?
*July 15, 2013 by tom*

**College Physics**

A wire P has resistance R. If the wire is stretched and its length is increased by 10%, what would be the percentage change in its resistance? (Assume the density of the wire remains constant) A) - 10% B) 0 % C) 10% D) 20% My thoughts: Since resistance is R = resistivity x ...
*November 24, 2011 by Andrew*

**physics Important please**

A metal wire has a resistance of 8.00Ω at a temperature of 20C. If the same wire has a resistance of 8.40Ω at 70C, what is the resistance of this wire in ohms when its temperature is −10C?
*November 12, 2013 by manu*

**physics**

The resistance of a coil copper wire at 20 degree celsius is 2.21 ohms. After a current of 10 amperes has been flowing in wire for two hours, the resistance of the coil was found o be 2.59 ohms. What is the temperature rise?
*October 9, 2014 by jun*

**physics**

A certain copper wire has a resistance of 12.0 \Omega.At what point along its length must the wire be cut so that the resistance of one piece is 5.0 times the resistance of the other?
*September 23, 2010 by rabiya*

**Physics resistance question**

A piece of copper wire of resistance R is cut into 10 equal lengths. These parts are connected in parallel. How does the joint resistance of the parallel combination compare with the original resistance of the single wire?
*February 21, 2012 by Anonymous*

**Chemistry**

In order to raise the temperature of 5.0 Kg of water from 20 deg. C to 30 deg. C, a 2.0 kg iron bar is heated and then dropped into the water. What should the starting temperature of the bar be? (Specific heat Fe is 0.22 cal/g-deg.)
*February 23, 2010 by Lexie*

**physics - ohms law**

how hot would a copper wire need to be for its resistance to be 2% larger than its value at room temperature (20 Centigrade)?
*January 24, 2012 by skills*

**Physics**

By what factor is the resistance of a copper wire changing when its temperature is increased from 20 degrees Celsius to 120 degrees Celsius? The temperature coefficient of resistivity for copper = 3.9 x 10^-3 (C)^-1.
*February 5, 2012 by Lindsay *

**physics**

A copper telephone wire has essentially no sag between poles 30 m apart on a winter day when the temperature is −16◦C. How much longer is the wire on a summer day when the temperature is 26 ◦C? Assume that the thermal coefficient of copper is constant ...
*January 22, 2015 by joe*

**physical**

Specific Heat. Copper has a specific heat of 0.092 cal/g/deg C. A 75 gram copper mass has been heated to a temperature of 100 degrees C. The copper is placed in thermal contact with 50 grams of water at 25 degrees C. What will be the final equilibrium temperature of the copper...
*November 23, 2013 by Anonymous*

**Physics**

Two wires are identical, except that one is aluminum and one is copper. The aluminum wire has a resistance of 0.835. What is the resistance of the copper wire? Take the resistivity of copper to be 1.72 x 10-8 Ωm, and that of aluminum to be 2.82 x 10-8 Ωm.
*June 5, 2013 by Tim*

**Physics**

1) Suppose that you wish to fabricate a uniform wire out of 1.15 g of copper. Assume the wire has a resistance R = 0.600 , and all of the copper is used. (a) What will be the length of the wire? m? (b) What will be the diameter of the wire? m? 2) A rectangular block of copper...
*October 4, 2010 by Max*

**Physics**

1) Suppose that you wish to fabricate a uniform wire out of 1.15 g of copper. Assume the wire has a resistance R = 0.600 , and all of the copper is used. (a) What will be the length of the wire? m? (b) What will be the diameter of the wire? m? 2) A rectangular block of copper...
*October 4, 2010 by Tommy*

**Physics**

You've made the finals of the Science Olympics! As one of your tasks, you're given 1.8g of copper and asked to make a wire, using all the metal, with a resistance of 1.3 Ohm. Copper has a density of 8900 kg/m^3. What length will you choose for your wire(in meters)? What ...
*February 17, 2010 by Anthony*

**physics**

the resistance of copper wire of length 1m is 0.1 ohm the diameter of the wire is 0.045cm find its specific resistance
*March 5, 2013 by amit kumar*

**Physics repost**

I know I have posted this question before but I have tried everything under the sun to no avail. Please help a clueless student!!!! A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, ...
*October 11, 2007 by Mary*

**Physics**

A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.70 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 10-2 /m. What is the average ...
*October 4, 2007 by Mary*

**Ap physics b**

A piece of copper wire is formed into a single circular loop of radius 11 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.65 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 10-2 /m. What is the average ...
*April 6, 2011 by christina*

**Plz help Physics-bobpursley**

Bob, please confirm if I got this right and if not, please help to solve 1)A wire has a resistance of 10 ohm at 20 deg celsius and 13.1 ohm at 100 deg celsius. Obtain a value for its temperature coefficient of resistance. ans I got is this= using Rt = Ro (1 + alpha(T-To)) 13.1...
*April 17, 2007 by Charles*

**Chemistry**

Copper has a specific heat of 0.387 J/gC. How much energy is required to raise the temperature of 140. g of copper from 17.5C to 154.0C?
*March 8, 2010 by Megan*

**Chemistry**

Copper has a specific heat of 0.387 J/gC. How much energy is required to raise the temperature of 215 g of copper from 47.0C to 164.0C?
*April 19, 2015 by Anonymous*

**Physic please help!**

A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.70 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 10-2 /m. What is the average ...
*October 9, 2007 by Mary*

**Physics**

What is the resistance of a 4.00 m length of copper wire having a diameter of 2.00 mm at a temperature of 20 degrees?
*May 10, 2011 by Anonymous*

**Physics**

Consider a piece of metal that is at 5 deg C. If it is heated until it has twice the internal energy, its temperature will be. a)556 deg C b)283 deg C c)273 deg C d)278 deg C e)10 deg C
*November 19, 2012 by S*

**College Physics II**

A steel wire and a copper wire, each of diameter 2.000 mm, are joined end to end. At 48.0C, each has an unstretched length of 2.000 m. The wires are connected between two fixed supports 4.000 m apart on a tabletop. The steel wire extends from x = −2.000 m to x = 0, the ...
*September 3, 2013 by Andrew*

**physics**

A copper telephone wire has essentially no sag between poles 34.0 m apart on a winter day when the temperature is −20.0C. How much longer is the wire on a summer day when the temperature is 32.0C? (Note: Table 19.1 is available for use in solving this problem.)
*December 13, 2014 by anonymous*

**college physics**

A 4m long copper wire has a diameter of 2mm and carries a current of 10A. Determine the ff: a. current density in the wire b. electric field c. potential difference between the ends of the wire d. resistance of the wire
*February 25, 2013 by Zell*

**physics**

a metal wire has a resistance of 8 Ohms at a temperature of 20 degrees. if the same wire has a resistance of 8.40 Ohms at 70 degrees. What is the resistance of this wire in Ohms when its temperature is -10 degree celsius
*November 13, 2013 by Anton*

**Physics**

What length of #22 B&S gauge copper wire is needed to make a resistance of 500 ohms? This is what I came up with but don't think it is correct. looked up diameter for #22 gauge wire = .643 mm and converted to m 6.46 * 10^-4. Used Eq. A = (pi)(d^2)/4 => A = (pi)(6.43 * 10^-4...
*September 7, 2012 by Kevin*

**PHYSICS**

A copper wire and an aluminium wire have length's in the ratio 3:2.diameters n the ratio 2:3 AND FORCES APPLIED IN THE RATIO 4:5 find the ratio of increase in length of the two wires.(Y FOR COPPER =1.1*1O^11 N/m^2,Y for aluminum=0.70*10^11 N/m^2). ans: 1)189:110
*February 4, 2013 by kalawathi*

**physics**

The drawing shows a copper wire (negligible resistance) bentinto a circular shape with a radius of 0.48 m. The radial sectionBC is fixed in place, while the copper bar ACsweeps around at an angular speed of 16 rad/s. The bar makeselectrical contact with the wire at all times. ...
*March 12, 2012 by Daniel*

**chemistry**

How much heat is needed to raise the temperature of 75 grams of copper from 35aC to 57aC? The specific heat of copper is 0.385 J/g aC.
*December 7, 2011 by mario*

**chemistry**

How much heat is needed to raise the temperature of 75 grams of copper from 35aC to 57aC? The specific heat of copper is 0.385 J/g aC.
*December 7, 2011 by mario*

**physics..resistance and all**

can someone tell me why when the length of a wire increase, the current decreases?? and why is it that, as the length of the wire increase, so too does the resistance..so y isn't the current the same increasing as the forumla V=IR shows that there is a proportional ...
*November 18, 2007 by AllyKat*

**physics**

One mile of copper wire has a resistance of 13 Ω. Using the wire to electrically connect two terminals that are half a mile apart, rank the following situations in order of increasing resistance. I. Use the full length of wire. II. Cut the wire in half and use only one ...
*April 16, 2012 by BOBBY*

**Phys 2**

I am having trouble figuring out this question: Part 1: A long staight wire carries a current due East. This wire creates, at point #1, a magnetic field that is derected at 40 deg below due South. From point #1, the wire is located: 50 deg below due North 50 deg below due ...
*March 16, 2011 by Sonia*

**Physics**

I am having trouble figuring out this question: Part 1: A long staight wire carries a current due East. This wire creates, at point #1, a magnetic field that is derected at 40 deg below due South. From point #1, the wire is located: 50 deg below due North 50 deg below due ...
*March 16, 2011 by Sonia*

**physics**

A potential difference of 12 V produces a current of 0.90 A in a piece of copper wire. What is the resistance of the wire?
*March 20, 2011 by maria*

**physics**

A potential difference of 12 V produces a current of 0.90 A in a piece of copper wire. What is the resistance of the wire?
*March 22, 2011 by maria*

**algebra**

A three quarter inch wire has 12 ohms resistance. How much resistance has the same length of half-inch wire, if resistance varies inversely as the square of the diameter?
*May 23, 2014 by Don*

**Physics 212**

Two copper wires have equal lengths, but the diameter of one is three times that of the other. a) The resistance of the thinner wire is _____ times that of the thicker wire: (Prove your work) 1) 3 2) 1/3 3) 9 4) 1/4
*January 6, 2014 by Marcu*

**math 156**

a worker makes 30000 a year. after 1 year he gets a raise of 5%. the next year he gets a raise of 10%. If he received no raise the first year, what percent increase would give him the same salary as consecutive raises of 5% and 10%? would it be 50%
*December 3, 2009 by Rmz*

**physics**

What is the resistance of a 7.4-m length of copper wire 1.2mm in diameter? The resistivity of copper is 1.6810−8Ω⋅m. R=_________
*February 7, 2014 by IM*

**Please Please Help-Physics**

I am having trouble figuring out this question: Part 1: A long staight wire carries a current due East. This wire creates, at point #1, a magnetic field that is derected at 40 deg below due South. From point #1, the wire is located: 50 deg below due North 50 deg below due ...
*March 16, 2011 by Sonia*

**Physics**

You've made the finals of the Science Olympics! As one of your tasks, you're given 1.1g of copper and asked to make a cylindrical wire, using all the metal, with a resistance of 1.7 Ohm. What length l will you choose for your wire? What diameter d will you choose for your wire?
*February 17, 2010 by Anthony*

**physical science **

An electric current heats a 225 g copper wire from 20.0 C to 40.0 C. How much heat was generated by the electric current? (ccopper = 0.093 cal/gm-deg)
*March 16, 2010 by Anonymous*

**physical science**

An electric current heats a 225 g copper wire from 20.0 C to 40.0 C. How much heat was generated by the electric current? (ccopper = 0.093 cal/gm-deg)
*July 16, 2010 by jerry*

**engineering physics 2**

A 19 m long piece of wire of density 8.34 g/m3 has a diameter of 12.593 mm. The resistiv- ity of the wire is 1.7e-8(ohm)(m) at 20 degrees celsius. The temperature coefficient for the wire is 0.0038(degrees celsius)^-1. Calculate the resistance of the wire at 20degrees Celsius...
*February 28, 2008 by David*

**science**

How much energy is required to raise the temperature of 22.8 g of copper from 30C to 1250C?
*February 27, 2012 by science*

**Chemistry**

I have this problem: How much heat energy is required to raise the temperature of 0.365kg of copper from 23.0 ∘C to 60.0 ∘C? The specific heat of copper is 0.0920 cal/(g⋅∘C). I did the equation using formula Heat= mass x change in temperature x specific...
*January 29, 2014 by mysterychicken*

**chemistry stoichiometry**

My chem teacher gave us this problem Twelve-gauge copper wire,like the kind commonly used in residential electrical systems, is roughly cylindrical and has a diameter of approximately .1040in. Copper's density is 8.92g/cubic cm and copper atoms have an approximate atomic ...
*September 9, 2007 by Julissa*

**physics**

Two wires have the same cross-sectional area and are joined end to end to form a single wire. The first wire has a temperature coefficient of resistivity of α1 =0.00603 (C)-1 and a resistivity of 5.00 x 10-7Ω m. For the second, the temperature coefficient is α2...
*January 25, 2013 by PLease HELP*

**PHYSICS 2**

Two wires have the same cross-sectional area and are joined end to end to form a single wire. The first wire has a temperature coefficient of resistivity of α1 =0.00603 (C)-1 and a resistivity of 5.00 x 10-7Ω m. For the second, the temperature coefficient is α2...
*January 25, 2013 by PLEASE HELP *

**Physics**

A copper wire that has been heated to 520 degrees Celsius for pliability is plunnged into 350 mL of water at 18 degrees Celsius. The final temperature of the copper and water bath is 31 degrees Celsius. Find the mass of the copper wire
*November 15, 2014 by Michelle*

**Physics**

A copper wire that has been heated to 520 degrees Celsius for pliability is plunged into 350 mL of water at 18 degrees Celsius. The final temperature of the copper and water bath is 31 degrees Celsius. Find the mass of the copper wire
*November 15, 2014 by Hemerla*

**physics **

A metal wire has a resistance of 8 ohm at a temperature of 20 degree celcius . If the same wire has a resistance of 8.40 ohm at 70 degree celcius , what is the resistance of this wire in ohms when its temperature is -10 degree celcius ?
*November 14, 2013 by rosa*

**physics **

A metal wire has a resistance of 8 ohm at a temperature of 20 degree celcius . If the same wire has a resistance of 8.40 ohm at 70 degree celcius , what is the resistance of this wire in ohms when its temperature is -10 degree celcius ?
*November 14, 2013 by rosa*

**chemistry**

A 55.0-g piece of copper wire is heated, and the temperature of the wire changes from 19 degrees C to 86 degrees C. The amount of heat absorbed is 343 cal. What is the specific heat of copper?
*August 4, 2008 by kayla*

**physics**

The specific heat capacity of copper is 0.092 calories per gram per degree Celsius. How much heat is required to raise the temperature of a 5 g piece of copper from 0C to 80C?
*December 13, 2009 by FALLON*

**physics**

An insulated copper wire is wrapped around an iron nail. The resulting coil of wire consists of 240 turns of wire that cover 1.8 cm of the nail, as shown in the figure . A current of 0.61 A passes through the wire. if the ferromagnetic properties of the nail increase the field...
*March 22, 2012 by physics im dying*

**physics**

A piece of copper wire has a resistance per unit length of 6.45*10-3 /m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.140 m. The ends of the wire are connected to a 12.0 V battery. Find the magnetic field strength at the center of the coil.
*February 11, 2008 by rick*

**Physics**

What is the resistance of a 4.00 m length of copper wire having a diameter of 2.00 mm at a temperature of 20 degrees? R= ? L= 4.00 m resistivity= 1.72 * 10^-8 ohm-meters A= ? A= pi*r^2 change 2 mm to .002m, square it and multiply by 3.14 I got .00001256 Is this right so far?
*May 9, 2011 by Anonymous*

**Chemistry**

In a laboratory, a student studies the absorption and transmission of light in order to analyze copper in brass and determine its percentage within the brass sample. He determines the amount of light absorbed by a sample by measuring the amount of light transmitted, all at a ...
*April 1, 2009 by Jessica*

**Physics **

A piece of copper wire has a resistance per unit length of 5.50 x 10^-3 Ω/m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.200 m. The ends of the wire are connected to a 12.0-V battery. Find the magnetic field strength at the center of the ...
*October 3, 2013 by Anonymous *

**physics**

Two wires have the same cross-sectional area and are joined end to end to form a single wire. The first wire has a temperature coefficient of resistivity of α1 =0.00480 (C)-1 and a resistivity of 4.90 x 10-5Ω m. For the second, the temperature coefficient is α2...
*January 22, 2013 by PLease HELP*

**PHYSICS**

Two wires have the same cross-sectional area and are joined end to end to form a single wire. The first wire has a temperature coefficient of resistivity of α1 =0.00603 (C)-1 and a resistivity of 5.00 x 10-7Ω m. For the second, the temperature coefficient is α2...
*January 26, 2013 by PLEASE HELP *

**physics PLEASE HELP**

Two wires have the same cross-sectional area and are joined end to end to form a single wire. The first wire has a temperature coefficient of resistivity of α1 =0.00480 (C)-1 and a resistivity of 4.90 x 10-5Ω m. For the second, the temperature coefficient is α2...
*January 22, 2013 by adam h.*

**physics**

A copper wire has a circular cross section with a radius of 3.75 mm. If the wire carries a current of 4.00 A, find the drift speed of the electrons in the wire. (Assume the density of charge carriers (electrons) in a copper wire is n = 8.46 *10^28 electrons/m^3.) thanks
*March 27, 2011 by Rachel*

**physics**

A copper wire has a circular cross section with a radius of 3.75 mm. If the wire carries a current of 4.00 A, find the drift speed of the electrons in the wire. (Assume the density of charge carriers (electrons) in a copper wire is n = 8.46 *10^28 electrons/m^3.) thanks
*March 27, 2011 by Rachel*

**chemistry**

If 125cal of heat is applied to a 60.0-g piece of copper at 20.0(Deg C), what will the final temperature be? The specific heat of copper is 0.0920cal/(g.degC)
*February 16, 2013 by Anonymous*

**Physics - calorie**

This was my problem: 4.) The specific heat capacity of copper is 0.092 cal/g*oC. Show that the amount of heat needed to raise the temperature of a 10-g piece of copper from 0oC to 100oC is 92 cal. How does this compare with the heat needed to raise the temperature for the same...
*September 20, 2009 by Mary*

**PSC 101**

How much heat is needed to raise the temperature of 130 g of copper from 31c to 77c ?
*September 23, 2013 by jm1003*

**science**

Im doing my resistance of a wire coursework. If a wire is longer why does the voltage increase and the current decrease?
*March 14, 2008 by Andrew Boynton*

**science**

If you have 10 lbs shrimp at 80 deg F how much ice would it take to reach 50 deg F in 10 minutes?
*August 7, 2013 by bill*

**Science**

Calculate the heat required to raise the temperature of 10kg of copper from 20C to 30C (S.H.C. of copper = 400J/kg k).
*February 25, 2014 by Ebenezer*

**series and parellel circuits**

ok here we go ... its a series-parellel circuit with 5 resistors. 12 volt battery- wire goes up then one wire branches up at 45 deg with a 10 ohm resistor then down at a 45 deg with a 10 ohm resistor, a second wire branches down at 45 deg with a 20 ohm resistor then up at a 45...
*May 21, 2012 by Dave*

**Maths**

3. Ohms law states that the current flowing in a circuit varies directly as the applied voltage and inversely as the resistance. In an experiment, the resistance was increased by triple the percentage by which the voltage was increased. A student calculated the percent change...
*November 17, 2012 by David*

**Physics!! Help!!!!!**

A wire of length L and cross-sectional area A has resistance R. What will be the resistance R_stretched of the wire if it is stretched to twice its original length? Assume that the density and resistivity of the material do not change when the wire is stretched. Express your ...
*February 15, 2012 by Melissa*

**Material Science**

Pure copper wire of diameter = 2.0 mm has an electrical resistance, R, of 0.005 ohm/m (upside down U/m). p = 8900 kg/ m cubed, Cp= 440 J/(kg K). Passage of electrical current produces thermal energy generation = I triangle V= I squared R (J/sec). Note that Units: Volts = J/...
*August 24, 2013 by Joy*

**science past year**

1.1. A resitance of 1.5ohm is connected in parallel with a resistance of 3 ohm. This combination is connected in series with a resistance of unknown resistance of value R. The circuit is then connected acress a 10 V supply. Calculate: 1.1.1. The value of the resistor R when a ...
*March 10, 2015 by kamil*

**Physics**

can someone tell me why when the length of a wire increase, the current decreases?? and why is it that, as the length of the wire increase, so too does the resistance..so y isn't the current the same increasing as the forumla V=IR shows that there is a proportional ...
*November 18, 2007 by AllyKat*

**physics**

Find the cross-sectional area of copper wire that is 55.4 m long and has a resistance of 0.943 ohms. The resistivity of copper is 1.79 x 10^-8 ohms m.
*April 28, 2011 by katie*