A tungsten wire is 1.50 m long and has a diameter of 1.00 mm. At 20°C a current of 50 mA flows through this wire
The temperature coefficient of resistivity for this tungsten is 4.5 × 10-3/C°, and its resistivity at 20°C is 5.6 × 10-8 ? ? m.
(a) What is the potential difference across the ends of this wire at 20°C?
(b) If the wire temperature increases by 100 C°, what potential difference across its ends is now required to produce a current of 50 mA?
(a) 5.3 mV (b) 7.8 mV
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