Question

6 At20 C, alength ofcopper wire has a resistance of 5 0 Ω What is its resistance when the wire ts heated to 80°C?It α-0004 at 200C. apoie) 01,2 Ω 07.5 Ω 0 622 10Ω 7. During a random lightning strike from a cloud to the ground, a current of 25,000 A lasts for 40 ( poin) ps. How much charge is transferred from the cloud to earth during that strike? 020 C 1.6C 0 10 C 2.5 C

Answer 1

$\\6)\\\\ R=R_{20}[&plus;\alpha\;\Delta T]\\\\ R=5.0\;[1 &plus;\;0.004\;(80-20)]\\\\ R=6.2\;\Omega\;<<<----answer\\\\\\ 7)\\\\ charge\;q=i\;t\\\\ charge\;q=25000\times 40\times 10^{-6}=1.0\;C\;<<<<<-------answer$