JAMB - Physics (2005 - No. 32)
The resistance of a piece of wire of length 20m has crossed-sectional area 8 x 10\(^{-6}\)m\(^2\)is?
[Resistivity of the wire = 4 x 10\(^{-7}\) Ω m]
[Resistivity of the wire = 4 x 10\(^{-7}\) Ω m]
5.0 Ω
0.5 Ω
10.0 Ω
1.0 Ω
Förklaring
since resistance R = \(\frac{p(l)}{a}\)
= \(\frac{4 \times 10^{-7} \times 20}{8.0 \times 10^{-6}}\)
R = 1.0 Ω
= \(\frac{4 \times 10^{-7} \times 20}{8.0 \times 10^{-6}}\)
R = 1.0 Ω