An electron in a metal is free to move anywhere but cannot leave the metal.
A thick wire and a thin wire of the same material are successively connected to the same circuit to find their respective resistance. Which one will have lower resistance ? Give reason.
The $V -I$ graphs for the two wires $A$ and $B$ are shown in the figure. If we connect both the wires one by one to the $v$ same battery which of the two will produce more heat per unit time ? Give justification for your answer.
A wire is $1.0\, m$ long, $0.2\, mm$ in diameter and has a resistance of $10 \, \Omega$. Calculate the resistivity of its material.
Two lamps, one is rated $100\, W$ at $220\, V$, and the other $60 \,W$ at $220\, V ,$ are connected in parallel to a $220\, V$ supply. Find the current drawn from the supply line.