$A$ block has dimensions $1 \ cm, 2 \ cm$ and $3 \ cm$. The ratio of the maximum resistance to the minimum resistance between any pair of opposite faces of the block is:

Explain how the resistance of a conductor depends on its dimensions.

$A$ thick wire is stretched so that its length becomes two times. Assuming that there is no change in its density,what is the ratio of the change in resistance of the wire to the initial resistance of the wire?

The resistance of the bulb filament is $100 \ \Omega$ at a temperature of $100^{\circ} C$. If its temperature coefficient of resistance is $0.005 \ ^{\circ} C^{-1}$,at what temperature will its resistance become $200 \ \Omega$ (in $^{\circ} C$)?

Arrange the following materials in increasing order of their resistivity: Nichrome,Copper,Germanium,Silicon.

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: