Which of the following is $NOT$ a unit of electrical energy?

Out of the two wires $X$ and $Y$ shown below,which one has greater resistance? Justify your answer.

What is the unit of resistance?

If five equal pieces of wire having $5\, \Omega$ resistance are made and connected in parallel,then their equivalent resistance will be $......$

$(a)$ Explain how a cell maintains current in a circuit.
$(b)$ In the circuit given below,the resistance of the path $xTy = 2 \, \Omega$ and that of $xZy = 6 \, \Omega$.
$(i)$ Find the equivalent resistance between $x$ and $y$.
$(ii)$ Find the current in the main circuit.
$(iii)$ Calculate the current that flows through the path $xTy$ and $xZy$.

Silicon is $......$