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 $Omega$)

Which of the following resistivity ( $\rho$ ) $v/s$ temperature $( T )$ curves is most suitable to be used in wire-bound standard resistors?

An electric toaster has a resistance of $60 \ \Omega$ at room temperature $\left(27^{\circ} C\right)$. The toaster is connected to a $220 \ V$ supply. If the current flowing through it reaches $2.75 \ A$,the temperature attained by the toaster is around: (given $\alpha = 2 \times 10^{-4} /{ }^{\circ} C$) (in $^{\circ} C$)

In order to quadruple the resistance of a uniform wire,a part of it is uniformly stretched so that the final length of the wire becomes $1.5$ times the original length. The fractional length of the stretched part is

The fact that the conductance of some metals rises to infinity at some temperature below a few Kelvin is called

Three copper wires of lengths and cross-sectional areas are $(l, A)$,$(2l, A/2)$,and $(l/2, 2A)$. Resistance is minimum in