The resistivity of all pure metals increases with an increase in temperature.

Define $1$ volt.

An electric bulb is connected to a $220 \ V$ generator. The current is $0.50 \ A$. What is the power of the bulb?

$A$ wire of length $L$ and resistance $R$ is stretched so that the length is doubled and area of cross-section is halved. How will its
$(a)$ resistance change?
$(b)$ resistivity change?

The amount of $2 \ A$ electric current is passed for $1 \ minute$ through a conducting wire. How much total electric charge will pass through this wire (in $C$)?

The electrical resistivity of a few materials is given below in ohm-metre. Which of these materials can be used for making the element of a heating device?

$A$. $6.84 \times 10^{-8} \, \Omega m$

$B$. $1.60 \times 10^{-8} \, \Omega m$

$C$. $1.00 \times 10^{-4} \, \Omega m$

$D$. $2.50 \times 10^{12} \, \Omega m$

$E$. $4.40 \times 10^{-5} \, \Omega m$

$F$. $2.30 \times 10^{17} \, \Omega m$