A certain lightbulb has a tungsten filament with a resistance of 18.5 N when cold and 136 N when hot. Assume the resistivity of tungsten varies linearly with temperature even over the large temperature range involved here. Find the temperature of the hot filament. Assume an initial temperature of 20.0°C. °C

A tungsten wire is used to determine the melting point of indium. The resistance of the tungsten wire is 2.221  at 20.0°C and increases to 4.307  as the indium starts to melt. αtungsten = 4.50 x 10−3 (°C)−1. What is the melting temperature of indium in °C?

What is the resistance of a 2.54-cm-diameter rod of pure silicon that is 20.0 cm long. What current flows through the rod when 1.00 × 103V is applied to it?

A copper wire of radius a = 0.240 mm has an aluminum jacket of outer radius b = 0.329 mm. There is a current i = 1.57 A in the composite wire. Take the resistivity for copper and aluminum to be 1.69 × 10-8Ω·m and 2.75 × 10-8Ω·m. Calculate the current in (a) the copper and (b) the aluminum. (c) If a potential difference V = 13.1 V between the ends maintains the current, what is the length in meters of the composite wire?

Question 3: A platinum resistance thermometer is a device that allows us to determine the temperature by measuring the resistance of a piece of pure platinum wire. In the interval between the freezing point of water and 700.0°C, the relationship between the resistance and the Celsius temperature Tc is accurately captured by the formula R = Ro (1 + A Tc + B (Tc)²) where A and B are constants determined by measurements at the ice point of water, the steam point of water, and the melting point of zinc (419.514°C). (a) If R equals 10.000 ohms at the freezing point of water, 13.946 ohms at the boiling point of water, and 24.174 ohms at the melting point of zinc, find RO, A, and B (b) If the resistance is measured to be 17.7 ohms, what is the temperature? (c) Plot R versus Tc in the range from 0°C to 700.0°C. Math tip: When we have several equations for several unknown variables, we can use the first equation to solve for one of the variables in terms of the others and then replace that…

A copper wire has a resistance of 0.565 N at 20.0°C, and an iron wire has a resistance of 0.597 N at the same temperature. At what temperature are their resistances equal? The temperature coefficient of resistivity for copper is 3.90 x 10-3(°C)-1 and for iron it is 5.00 x 10-3(°C)-1. °C

A copper wire of radius a = 0.256 mm has an aluminum jacket of outer radius b = 0.337 mm. There is a current i = 1.59 A in the composite wire. Take the resistivity for copper and aluminum to be 1.69 × 10-8Ω·m and 2.75 × 10-8Ω·m. Calculate the current in (a) the copper and (b) the aluminum. (c) If a potential difference V = 15.0 V between the ends maintains the current, what is the length in meters of the composite wire?

A tungsten wire has a radius of 0.085 mm and is heated from 20.0 to 1344 °C. The temperature coefficient of resistivity is a = 4.5 x 10 3 (C°) 1. When 100 V is applied across the ends of the hot wire, a current of 1.3 A is produced. How long is the wire? Neglect any effects due to thermal expansion of the wire. Number Units