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In a wire of cross-section radius r, fre...

In a wire of cross-section radius `r`, free electrons travel with drift velocity `v` when a current `I` flows through the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is `2v`?

A

2I

B

I

C

I/2

D

I/4

Text Solution

Verified by Experts

The correct Answer is:
C
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MOTION-CURRENT ELECTRICITY-EXERCISE -1 (OBJECTIVE PROBLEMS NEET)
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  2. Two wires each of radius of cross section r but of different materials...

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  3. In a wire of cross-section radius r, free electrons travel with drift ...

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  4. An insulating pipe of cross-section area A contains an electrolyte whi...

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  5. A uniform copper wire carries a current i amperes and has p carries pe...

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  6. In the presence of an applied electric field (vecE) in a metallic con...

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  7. A wire has non-uniform cross-section as shown in fig. steady current f...

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  8. Specific resistance of a wire depends on its

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  9. If the electrical resistance of a typical substance suddenly drops to ...

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  10. The resistance of wire is 20 Omega. The wire is stretched to three tim...

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  11. The dimensions of a mangnin block are 1 cm xx 1 cm xx100 cm The electr...

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  12. Iron and silicon wires are heated form 30^(@)C to 50^(@)C. The correct...

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  13. When the resistance of copper wire is 0.1 Omega and the radius is 1mm,...

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  14. When a resistance wire is passed through a die the cross-section area ...

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  15. In the following diagram two parallelopiped A and B are of the same th...

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  16. A conductor with rectangular cross section has dimensions (axx2axx4a) ...

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  17. A piece of copper and another of germanium are cooled from room temper...

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  18. A cylindrical copper rod is reformed to twice its original length with...

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  19. The length of a conductor is halved. Its conductance will be

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  20. The current in a metallic conductor is plotted against voltage at two ...

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