Physics · 2021
JEE Main · 16 March 2021, Shift 1 · Q19
A conducting wire of length ' l ', area of cross-section A and electric resistivity ρ is connected between the terminals of a battery. A potential…
A conducting wire of length ' $\displaystyle l$ ', area of cross-section A and electric resistivity $\displaystyle \rho$ is connected between the terminals of a battery. A potential difference V is developed between its ends, causing an electric current.
If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be :
Official answer
(3)
$\displaystyle \frac{1}{4} \frac{\mathrm{VA}}{\rho l}$
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JEE Main 2021 Physics question, with the answer from NTA’s final answer key. Where our answers come from.