Find the resistance of a cube of edge $60 \text{ cm}$,made of a material of specific resistance $60 \times 10^{-8} \Omega \text{ m}$.

$A$ hollow cylindrical conductor has a length of $3.14 \, m$, while its inner and outer diameters are $4 \, mm$ and $8 \, mm$ respectively. The resistance of the conductor is $n \times 10^{-3} \, \Omega$. If the resistivity of the material is $2.4 \times 10^{-8} \, \Omega \, m$, the value of $n$ is $..........$

The electric bulbs have tungsten filaments of same length. If one of them gives $60 \, W$ and the other $100 \, W$,then:

Wires $P$ and $Q$ have the same resistance at ordinary (room) temperature. When heated,the resistance of $P$ increases and that of $Q$ decreases. We conclude that:

The solids which have the negative temperature coefficient of resistance are:

The resistance of the filament of an 'incandescent' bulb increases with an increase in temperature. If $R_{100}$,$R_{60}$,and $R_{40}$ are the resistances of $100 \ W$,$60 \ W$,and $40 \ W$ bulbs at room temperature,respectively,then: