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प्रश्न
Define the term drift velocity.
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उत्तर
The average velocity of all the free electrons in the conductor with which they get drifted towards the positive end of the conductor under the influence of an external electric field is called the drift velocity.
संबंधित प्रश्न
Derive an expression for drift velocity of free electrons.
How does drift velocity of electrons in a metallic conductor vary with increase in temperature? Explain.
Derive an expression for drift velocity of free electrons in a conductor in terms of relaxation time.
Consider the following statements.
(A) Free-electron density is different in different metals.
(B) Free-electron density in a metal depends on temperature.
Thomson Effect is caused _______________ .
At room temperature, copper has free electron density of 8.4 × 1028 per m3. The copper conductor has a cross-section of l0−6 m2 and carries a current of 5.4 A. The electron drift velocity in copper is:
The identical conductors maintained at same temperature are given potential difference in the ratio 1 : 2. Then the ratio of their drift velocities is ______.
- Consider circuit in figure. How much energy is absorbed by electrons from the initial state of no current (ignore thermal motion) to the state of drift velocity?
- Electrons give up energy at the rate of RI2 per second to the thermal energy. What time scale would one associate with energy in problem (a)? n = no of electron/volume = 1029/m3, length of circuit = 10 cm, cross-section = A = (1mm)2
The potential difference applied across a given conductor is doubled. How will this affect (i) the mobility of electrons and (ii) the current density in the conductor? Justify your answers.
Why do free electrons in a metal move randomly when no electric field is present?
What is the average velocity of electrons when no electric field is present?
