Question

Learning Goal: Examine the dependence of resistivity and resistance of a wire on temperature and how it affects the potential difference across the terminals of the wire. Introduction: A current of 65 milli-amperes (mA) flows through a wire of length L= 1.7 meters long and diameter of d= 1.15 millimeters at a temperature of T0= 20 °C; the wire's resistivity at this temperature is ρ0= 5.33×10−8 Ω ∙ m. The temperature coefficient of resistivity of the material is α= 4.6×10−3/C°.

Part A What is the resistance of the wire at 20 °C? Express your answer to three significant figures and include the appropriate units.

Part B (b) What is the potential difference across the ends of this wire at 20 °C in milli-volts (mV)? Express your answer to three significant figures and include the appropriate units.

Part C (c) If the wire temperature increases to 103 C°, what potential difference (in mV) across its ends is now required to produce a current of 65 mA? Express your answer to three significant figures and include the appropriate units.

Answer 1