JEE Mains · Physics · STD 12 - 3. current electricity
Drift speed of electrons, when \(1.5\, A\) of current flows in a copper wire of cross section \(5\, mm^2\), is \(v\). If the electron density in copper is \(9 \times 10^{28}\, m^3\) the value of \(v\) in \(mm/s\) is close to (Take charge of electron to be \(= 1.6 \times 10^{-19}\, C\))
- A \(0.02\)
- B \(3\)
- C \(2\)
- D \(0.2\)
Answer & Solution
Correct Answer
(A) \(0.02\)
Step-by-step Solution
Detailed explanation
\(\mathrm{i}=\mathrm{ne} \mathrm{AV}_{\mathrm{d}}\) \(1.5=9 \times 10^{28} \times 1.6 \times 10^{-19} \times 5 \times \mathrm{Vd}\) \(\mathrm{Vd}=0.02\)
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