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

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 different conductors have the same resistance at $0\,^{\circ}C.$ It is found that the resistance of the first conductor at $t_1\,^{\circ}C$ is equal to the resistance of the second conductor at $t_2\,^{\circ}C.$ The ratio of the temperature coefficients of resistance of the conductors,$\frac{\alpha_1}{\alpha_2}$ is

The resistivity of iron is $1 \times 10^{-7} \, \Omega \cdot m$. The resistance of an iron wire of a particular length and thickness is $1 \, \Omega$. If the length and the diameter of the wire are both doubled, then the resistivity in $\Omega \cdot m$ will be:

$A$ uniform wire of resistance $R$ is uniformly compressed along its length,until its radius becomes $n$ times the original radius. Now,the resistance of the wire becomes:

An aluminium (resistivity $\rho = 2.2 \times 10^{-8} \Omega \cdot m$) wire of diameter $1.4 \text{ mm}$ is used to make a $4 \Omega$ resistor. The length of the wire is: (in $\text{ m}$)