Physics
What length of copper wire of specific resistance 1.7 x 10-8 Ω m and radius 1 mm is required so that it's resistance is 2 Ω.
Related Questions
A wire of resistance 3 ohm and length 10 cm is stretched to length 30 cm. Assuming that it has a uniform cross-section, what will be it's new resistance?
A wire of resistance 9 Ohm having length 30 cm is tripled on itself. What is it's new resistance?
The filament of a bulb takes a current 100 mA when potential difference across it is 0.2 V. When the potential difference across it becomes 1.0 V, the current becomes 400 mA. Calculate the resistance of filament in each case and account for the difference.
The specific resistance of copper, silver and constantan are 1.78 x 10-6 Ω cm, 10-6 Ω cm and 48 x 10-6 Ω cm respectively.
(i) Identify the best conductor.
(ii) Give reason for your answer above.