Electric power is also called $BOTU$.

$(i)$ Name and state the law that gives the relationship between the current through a conductor and the potential difference across its two terminals. Also,express this law mathematically.
$(ii)$ Draw the $V-I$ graph for this law. Justify your answer.
$(iii)$ Write the name and use of the circuit components whose symbols are given below:
$(a)$ $A$ resistor with an arrow through it.
$(b)$ $A$ circle with a dot inside,connected to two lines.

Define resistivity of a material.

If you connect three resistors having values $2 \, \Omega$, $3 \, \Omega$, and $5 \, \Omega$ in parallel, will the value of total resistance be less than $2 \, \Omega$, greater than $5 \, \Omega$, or lie between $2 \, \Omega$ and $5 \, \Omega$? Explain.

Which alloy is used to make the heating element (resistance wire) in an electric iron?

$A$ cylinder of a material is $10\, cm$ long and has a cross-section of $2\, cm^{2}$. If its resistance along the length is $20\, \Omega$,what will be its resistivity in number and units?