A (b) If the wire is heated to 40.0°C while the 7.0-V potential difference is maintained, what is the resulting current in the wire?  A

A light bulb filament is made of tungsten wire with a resistivity, at room temperature (20°C), of 5.6 x 10-8 Q.m and a temperature coefficient of 0.0045 (°C)-1 The wire is 50 cm long and has a diameter of 45 Um. (a) What is the resistance of the filament at room temperature (20°C)? (Put this answer in the box) (b) What is the resistance of the filament at a typical operating temperature of 3000°C ? Answer:

(a) A 35.5-m length of copper wire at 20.0°C has a radius of 0.23 mm. If a potential difference of 7.0 V is applied across the length of the wire, determine the current in the wire. (Use the values in the following table.) Resistivities and Temperature Coefficients of Resistivity for Various Materials (at 20°C) Material Silver A Copper Gold Aluminum Tungsten Iron Platinum Lead Nichrome a Carbon Germanium Silicon Glass Hard rubber Sulfur Quartz (fused) Resistivity (2. m) 1.59 x 107 1.7 x 10-8 2.44 x 10-8 2.82 x 10 5.6 x 107 10.0 x 10 11 x 10 -8 -8 0.46 -8 640 22 x 10-8 3.5 x 107 -8 -8 150 x 10- -8 -5 1010-1014 ≈1013 1015 75 x 1016 Temperature Coefficient of Resistivity [(°C)-¹] 3.8 x 10 -3 3.9 × 10-3 3.4 x 10-3 3.9 x 107 5.0 x 10 4.5 x 10-3 3.92 x 10 -3 -3 0.4 x 107 -3 3.9 × 10-3 -3 -3 -0.5 x 107 -48 x 10-3 -75 x 10-3 aA nickel-chromium alloy commonly used in heating elements. (b) If the wire is heated to 40.0°C while the 7.0-V potential difference is maintained, what is the resulting…

A certain material has a resistance of 150 22 at 20°C. The material is then heated to 800°C, calculate the new resistance. Given the temperature coefficient of resistivity of the material is 3.65x10.³ °C-¹.

QUESTION 1 Consider a carbon rod resistor that has a uniform cross-sectional area of 5.00 mm-. When a potential difference of 3.5 V is applied across the ends of the rod, the rod carries a current of 0.40 A. Find the rod's length (in cm) if its resistivity is p=3.5 x 10 5 Q. m.

(a) A 35.1-m length of copper wire at 20.0°C has a radius of 0.23 mm. If a potential difference of 7.0 V is applied across the length of the wire, determine the current in the wire. (Use the values in the following table.) Resistivities and Temperature Coefficients of Resistivity for Various Materials (at 20°C) Material Resistivity(Ω · m) Temperature Coefficientof Resistivity [(°C)−1] Silver 1.59 ✕ 10−8 3.8 ✕ 10−3 Copper 1.7 ✕ 10−8 3.9 ✕ 10−3 Gold 2.44 ✕ 10−8 3.4 ✕ 10−3 Aluminum 2.82 ✕ 10−8 3.9 ✕ 10−3 Tungsten 5.6 ✕ 10−8 4.5 ✕ 10−3 Iron 10.0 ✕ 10−8 5.0 ✕ 10−3 Platinum 11 ✕ 10−8 3.92 ✕ 10−3 Lead 22 ✕ 10−8 3.9 ✕ 10−3 Nichromea 150 ✕ 10−8 0.4 ✕ 10−3 Carbon 3.5 ✕ 10−5 −0.5 ✕ 10−3 Germanium 0.46 −48 ✕ 10−3 Silicon 640 −75 ✕ 10−3 Glass 1010–1014   Hard rubber ≈1013   Sulfur 1015   Quartz (fused) 75 ✕ 1016   aA nickel–chromium alloy commonly used in heating elements.  ??A(b) If the wire is heated to 36.0°C while the 7.0-V potential difference is…

(a) A 34.9-m length of copper wire at 20.0°C has a radius of 0.29 mm. If a potential difference of 7.0 V is applied across the length of the wire, determine the current in the wire. (Use the values in the following table.) Resistivities and Temperature Coefficients of Resistivity for Various Materials (at 20°C) Material Resistivity(Ω · m) Temperature Coefficientof Resistivity [(°C)−1] Silver 1.59 ✕ 10−8 3.8 ✕ 10−3 Copper 1.7 ✕ 10−8 3.9 ✕ 10−3 Gold 2.44 ✕ 10−8 3.4 ✕ 10−3 Aluminum 2.82 ✕ 10−8 3.9 ✕ 10−3 Tungsten 5.6 ✕ 10−8 4.5 ✕ 10−3 Iron 10.0 ✕ 10−8 5.0 ✕ 10−3 Platinum 11 ✕ 10−8 3.92 ✕ 10−3 Lead 22 ✕ 10−8 3.9 ✕ 10−3 Nichromea 150 ✕ 10−8 0.4 ✕ 10−3 Carbon 3.5 ✕ 10−5 −0.5 ✕ 10−3 Germanium 0.46 −48 ✕ 10−3 Silicon 640 −75 ✕ 10−3 Glass 1010–1014   Hard rubber ≈1013   Sulfur 1015   Quartz (fused) 75 ✕ 1016   (b) If the wire is heated to 32.0°C while the 7.0-V potential difference is maintained, what is the resulting current in the wire?