does not contribute to v d (Chapter , Textbook of Class XI). v d , thus is only due to applied electric field on the electron. . The relation j = ρ v should be applied to each type of charge carriers separately.
In a conducting wire, the total current and charge density arises from both positive and negative charges: j = ρ + v + + ρ – v – ρ = ρ + + ρ – Now in a neutral wire carrying electric current, ρ + = – ρ – Further, v + ~ which gives ρ = j = ρ – v Thus, the relation j = ρ v does not apply to the total current charge density. . Kirchhoff’s junction rule is based on conservation of charge and the outgoing currents add up and are equal to incoming current at a junction. Bending or reorienting the wire does not change the validity of Kirchhoff’s junction rule.
a steady value of . A. What is the steady temperature of the heating element if the room temperature is . °C?
Temperature coefficient of resistance of nichrome averaged over the temperature range involved is . × – °C – . . Determine the current in each branch of the network shown in Fig.
. : FIGURE . . (a) In a metre bridge [Fig.
. ], the balance point is found to be at . cm from the end A , when the resistor Y is of . Ω .
Determine the resistance of X . Why are the connections between resistors in a Wheatstone or meter bridge made of thick copper strips? (b) Determine the balance point of the bridge above if X and Y are interchanged. (c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge?
Would the galvanometer show any current? . A storage battery of emf . V and internal resistance .
Ω is being charged by a V dc supply using a series resistor of . Ω . What is the terminal voltage of