On which factors does the resistlvity of conducting wire depend?
State with the help of a circuit diagram an activity to find the resistance ${ }^{\prime} R^{\prime}$ of a given wire. A current of $0.2\, A$ passes through a resistor of $20 \Omega$. Find the potential difference across its ends.
$(a)$ $(i)$ What is meant by saying that the potential difference between two points is $1$ volt ?
$(ii)$ How much energy is given to $5$ coulomb of charge passing through a $12 \,V$ battery ?
$(b)$ Describe an activity with necessary electric circuit drawn to study the factors on which the resistance of a conducting wire depends.
The equivalent resistance between points $A$ and $B$ in the following electric circuit is $.....$
Calculate the equivalent resistance between the points $A$ and $B$ in the following combination.