Question

Calculate the current in an aluminium wire of length 50 cm and cross sectional area 5.0 mm² for voltage drop of 2.5 volts. The resistivity of the aluminium is 2.5 × 10 ^{- 8} Ω m.

1. 1000 ampere
2. 100 ampere
3. 10 ampere
4. 1 ampere

Answer 1

Correct Answer - Option 1 : 1000 ampere

\(\begin{array}{l} R\; = \;\rho \frac{l}{A}\; = \;2.5 \times {10^{ - 8}} \times \frac{{0.5}}{{5 \times {{10}^{ - 6}}}}\; = \;0.0025\;{\rm{\Omega }}\\ i\; = \;\frac{V}{R}\; = \;\frac{{2.5}}{{0.0025}}\; = \;1000\;ampere \end{array}\)