Two square metal plates $A$ and $B$ are of the same thickness and material. The side of $B$ is twice that of $A$. These are connected as shown in series. If the resistances of $A$ and $B$ are denoted by $R_A$ and $R_B,$ then $(R_A/R_B)$ is

At room temperature $(27.0^{\circ} C)$,the resistance of a heating element is $100\; \Omega$. What is the temperature (in $^{\circ} C$) of the element if the resistance is found to be $117\; \Omega$,given that the temperature coefficient of the material of the resistor is $1.70 \times 10^{-4}\; ^{\circ} C^{-1}$?

For wiring in the home,one uses $Cu$ wires or $Al$ wires. What considerations are involved in this?

$A$ wire of radius $r$ has resistance $R$. If it is stretched to a radius of $\frac{3r}{4}$,its resistance becomes

$A$ wire of a certain material is stretched slowly by $10 \%$. Its new resistance and specific resistance become respectively:

In the following,$I$ refers to current and other symbols have their usual meaning. Choose the option that corresponds to the dimensions of electrical conductivity.