A current `I` is passing through a wire having two sections `P` and `O` of uniform diameters `d` and `d//2` respectively. If the mean drift velocity of electrons in section `P` and `Q` is denoted by `v_(P)` and `v_(Q)` respectively, thenA. `v_(P) = v_(Q)`B. `v_(P) = (1)/(2) v_(Q)`C. `v_(P) = (1)/(4) v_(Q)`D. `v_(P) = 2v_(Q)`

A current `I` is passing through a wire having two sections `P` and `O

1.	A current `I` is passing through a wire having two sections `P` and `O` of uniform diameters `d` and `d//2` respectively. If the mean drift velocity of electrons in section `P` and `Q` is denoted by `v_(P)` and `v_(Q)` respectively, thenA. `v_(P) = v_(Q)`B. `v_(P) = (1)/(2) v_(Q)`C. `v_(P) = (1)/(4) v_(Q)`D. `v_(P) = 2v_(Q)`
Answer» Correct Answer - C (c ) Drift velocity `v_(d) = (i)/(n e A) implies v_(d) prop (1)/(A)` or `v_(d) prop (1)/(d^(2))` `implies (v_(P))/(v_(Q)) = ((d_(Q))/(d_(P)))^(2) = ((d // 2)/(d))^(2) = (1)/(4) implies v_(P) = (1)/(4) v_(Q)`

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