The specific resistance of a wire is $\rho$,its volume is $3\,m^3$ and its resistance is $3\,\Omega$. Then its length will be:

Three bulbs of $40\,W$,$60\,W$,and $100\,W$ are connected in series with a $220\,V$ supply. Which bulb has the minimum resistance?

Two wires of same length and thickness having specific resistances $6 \, \Omega \, cm$ and $3 \, \Omega \, cm$ respectively are connected in parallel. The effective resistivity is $\rho \, \Omega \, cm$. The value of $\rho$ to the nearest integer is ..... .

Two solid conductors are made of the same material,have the same length,and have the same resistance. One of them has a circular cross-section of area $A_{1}$ and the other has a square cross-section of area $A_{2}$. The ratio $\frac{A_{1}}{A_{2}}$ is

$A$ copper wire of length $L$ and diameter $D$ is to be reshaped into another wire so as to have minimum resistance. For this,we should:

The resistance of a wire is $2.5 \Omega$ at a temperature $373 \ K$. If the temperature coefficient of resistance of the material of the wire is $3.6 \times 10^{-3} \ K^{-1}$,its resistance at a temperature $273 \ K$ is nearly: (in $\Omega$)