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CBSE Notes 2011-2012 » Forums » Open Discussion

physics

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Nikita agrawal's picture
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Joined: 30/08/2011

i am unable to understand what is drift velocity ans also temperature effect on electricity...........plz help me

kumarasmit's picture
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Joined: 06/09/2011
Drift velocity and effect of temperature on electricity

It is the average velocity that a particle, such as an electron attains due to an electric field. In general, an electron will 'rattle around' in a conductor at the Fermi velocity randomly. An applied electric field will give this random motion a small net velocity in one direction.
Answer of your second question is-(1) For conductors, an increase in temperature reduces the current carrying capacity. For insulators, it has just the opposite effect; an increase in temperature increases the current carrying capacity. Second thing is that Temperature can affect the conductivity of materials. This will affect the current that flows through it if the voltage is set.

The conductivities of most metals decrease as the temperature increases.The reasons for these behaviors is faitly complicated

kumarasmit