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JEE Mains · Physics · STD 12 - 3. current electricity
A copper rod of cross-sectional area \(A\) carries a uniform current \(I\) through it. At temperature \(T\), if the volume charge density of the rod is \(\rho \), how long will the charges take to travel a distance \(d\) ?
- A \(\frac{{2\rho dA}}{{IT}}\)
- B \(\frac{{2\rho dA}}{{I}}\)
- C \(\frac{{\rho dA}}{{I}}\)
- D \(\frac{{\rho dA}}{{IT}}\)
Answer & Solution
Correct Answer
(C) \(\frac{{\rho dA}}{{I}}\)
Step-by-step Solution
Detailed explanation
Charge density \(\rho=\frac{\text { charge }}{\text { volume }}=\frac{q}{A d} \Rightarrow q=\rho A d\) Also, \(q=I T \Rightarrow T=\frac{q}{I}=\frac{\rho A d}{I}\)
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