2.
A wire has a non-uniform cross-section as shown in the figure. If a steady current is flowing through it, then the drift speed of the electrons-
3.
Pieces of copper and of silicon are initially at room temperature. Both are heated to temperature T. The conductivity of
6.
The figure shows a network of currents. The current I will be-
9.
The current in a device varies with time t as I = 6t where I is in mA and t is in s. The amount of charge that passes through the device during t=0 s to t=3 s is-
10.
A cell of emf E is connected across an external resistance R. When current 'I' is drawn from the cell, the potential difference across the electrodes of the cell drops to V. The internal resistance 'r' of the cell is-
