Advertisements
Advertisements
प्रश्न
A steady current flows in a metallic conductor of non-uniform cross-section. Which of these quantities is constant along the conductor: current, current density, electric field, drift speed
उत्तर
When a steady current flows in a metallic conductor of a non-uniform cross-section, the current flowing through the conductor is constant. Current density, electric field, and drift speed are inversely proportional to the area of cross-section. Therefore, they are not constant.
APPEARS IN
संबंधित प्रश्न
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.
Answer the following question.
How is the drift velocity in a conductor affected with the rise in temperature?
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.
Ten identical cells connected in series are needed to heat a wire of length one meter and radius ‘r’ by 10ºC in time ‘t’. How many cells will be required to heat the wire of length two meter of the same radius by the same temperature in time ‘t’?
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.
Which of the following characteristics of electrons determines the current in a conductor?