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A constant voltage is applied across a wire of constant length then how drift velocity of electrons depends on area of cross-section of wire.

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The correct Answer is:
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By conservation of linear momentum `(80 + 40) (2.5) = 80 (0) + 40 (v) rArr = v = 7.5 m//s`
work done `= DeltaKE = (1)/(2) 40 (7.5)^(2) - (1)/(2) (80 + 40) (2.5)^(2) = 750 J`
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ALLEN -CURRENT ELECTRICITY-EX.II
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  3. Lengths and cross-sectional areas of three copper wires are (l, A ), (...

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  9. As the temperature of a metallic resistor is increased,the product of ...

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  10. What will b e the equivalent resistance b etween the A and D?

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  11. In the arrangement of resistances shown in the circuit. The potential...

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  14. When no current is passed through a conductor,

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  16. Internal resistance of a cell depends on

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  17. The resistance of the circuit between A and B is:-

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  18. The number of free electrons per 100 mm of ordinary copper wire is 2xx...

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  19. The potential difference between the terminals of a cells is found to ...

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  20. What is the reading of ammeter is adjoining circuit diagram.

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