Advertisements
Advertisements
Question
Answer the following question.
How is the drift velocity in a conductor affected with the rise in temperature?
Advertisements
Solution
Drift velocity is dependent on temperature i.e. When the temperature is increased the electrons become kinetically excited means rise in temperature causes atoms to vibrate more, which increases the number of collisions electron have on their way through the wire and decreases the drift velocity.
APPEARS IN
RELATED QUESTIONS
One of your friends says that he has read in the previous chapters that there can be no electric field inside a conductor. Consequently, there can be no current through it. What is the fallacy of this argument?
A fan with copper winding in its motor consumes less power compared to a similar fan with aluminium winding. Explain.
Does a conductor become charged when a current is passed through it?
The amount of charge that passes in time t through a cross-section of a wire is
Q(t) = At2 + Bt + C.
(a) Write the dimensional formulae for A, B and C.
(b) If the numerical values of A, B and C are 5, 3 and 1, respectively, in S.I units, find the value of the current at t = 5 s.
Assertion: A current flows in a conductor only when there is an electric field within the conductor.
Reason: The drift velocity of electron in presence of electric field decreases.
A hank of uninsulated wire consisting of seven and a half turns is stretched between two nails hammered into a board to which the ends of the wire are fixed. The resistance of the circuit between the nails is determined with the help of electrical measuring instruments. Determine the proportion in which the resistance will change if the wire is unwound so that the ends remain to be fixed to the nails.
Assertion: When current through a bulb decreases by 0.5%, the glow of bulb decreases by 1%.
Reason: Glow (Power) which is directly proportional to square of current.
A current of 5A is passing through a non-linear magnesium wire of cross-section 0.04m2. At every point, the direction of current density is at an angle of 60° with the unit vector of area of cross-section. The magnitude of electric field at every point of the conductor is ______.
Resistivity of magnesium = 44 × 10-8 Ωm
