Rankers Physics

Relation between Current and Drift Velocity: Practice Problem & Solution

The specific resistance of a wire :
varies with its length
varies with its cross-section
varies with its mass of wire
does not depend on its length, cross-section and mass of wire

Solution Explained:

To solve this problem, we apply the core principles of Relation between Current and Drift Velocity. Understanding the underlying formula is key to arriving at the correct answer below:

Specific resistance is property of substance it doesn't depend on any other physical factor

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Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. Assertion (A): The drift speed of electrons in metals is small (in the order of a few \(mm/s\)) and the charge of an electron is also very small (\(= 1.6 \times 10^{-19} C\)), yet we can obtain a large current in a metal. Reason (R): At room temperature, the thermal speed of electron is very high (about \(10^7\) times the drift speed).  
2. The mean free path of electrons in a metal is $4 \times 10^{-8}\text{ m}$. The electric field which can give on an average $2\text{ eV}$ energy to an electron in the metal will be in units $\text{V/m}$. (2009)
3. Assertion (A): The electric bulb glows immediately when switch is on. Reason (R): The drift velocity of electrons in a metallic wire is very high (near speed of light).  
4. Estimate the average drift speed of conduction electrons in a conductor of cross-sectional area \(10^{-7}\text{ m}^2\) carrying current of \(1.5\text{ A}\). The number density of conduction electrons is \(8.5 \times 10^{28}\text{ m}^{-3}\).
5. A charged particle having drift velocity of $7.5 \times 10^{-4} \text{ m s}^{-1}$ in an electric field of $3 \times 10^{-10} \text{ Vm}^{-1}$, has a mobility in $\text{m}^2 \text{ V}^{-1} \text{ s}^{-1}$ of : (2020)