(i) Derive an expression for drift velocity of electrons in a conductor. Hence deduce Ohm's law.(ii) A wire whose cross-sectional area is increasing linearly from its one end to the other, is connected across a battery of V volts. Which of the following quantities remain constant in the wire ?(a) drift speed (b) current density(c) electric current(d) electric field Justify your answer.

(i) Derive an expression for drift velocity of electrons in a conducto

1.	(i) Derive an expression for drift velocity of electrons in a conductor. Hence deduce Ohm's law.(ii) A wire whose cross-sectional area is increasing linearly from its one end to the other, is connected across a battery of V volts. Which of the following quantities remain constant in the wire ?(a) drift speed (b) current density(c) electric current(d) electric field Justify your answer.
Answer» Solution :(ii) Out of four quantities given here only (c) electric CURRENT remains constant in the wire. All theremaining three quantities NAMELY : (a) drift speed, (B) current density, and (d) electric field do not remain constant because their values depend upon the cross-section area of conductorwhich is increasing linearly from one end to the other.

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