Advertisements
Advertisements
प्रश्न
A potential difference (V) is applied across a conductor of length 'L' and cross-sectional area 'A'.
How will the drift velocity of electrons and the current density be affected if another identical conductor of the same material were connected in series with the first conductor? Justify your answers.
Advertisements
उत्तर
We know,
Drift velocity, `v_d = (eE)/mtau ⇒ (eV)/(mL)tau`
Current density, J = `I/A`
If another conductor of the same length will be connected in series. I will remain the same and my potential will become half. So, drift velocity will become half and current density will remain the same.
APPEARS IN
संबंधित प्रश्न
Explain the term ‘drift velocity’ of electrons in conductor. Hence obtain the expression for the current through a conductor in terms of ‘drift velocity’.
Electrons are emitted by a hot filament and are accelerated by an electric field, as shown in the figure. The two stops at the left ensure that the electron beam has a uniform cross-section.
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 drift velocity of a free electron inside a conductor 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
Explain how free electrons in a metal at constant temperature attain an average velocity under the action of an electric field. Hence, obtain an expression for it.
What is the average velocity acquired by free electrons in a conductor under the influence of an electric field called?
Which expression gives the drift velocity in terms of electric field \[E\], relaxation time \[\tau\], electronic charge \[e\], and electron mass \[m\]?
With what do electrons continuously collide in a conductor?
What is the effect of collisions on the acceleration produced by an electric field?
