Resistance of a metal wire of length $1\, m$ is $26\, \Omega$ at $20^{\circ} C$. If the diameter of the wire is $0.3\, mm$,what will be the resistivity of the metal at that temperature?

An electric bulb of resistance $480 \Omega$ is connected to a $220 \text{ V}$ main. Find the amount of electrical energy consumed in $10 \text{ seconds}$. (in $J$)

$(a)$ 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 $xZy$.

$(a)$ In the circuit shown, connect a nichrome wire of length $L$ between points $X$ and $Y$ and note the ammeter reading.
$(i)$ When this experiment is repeated by inserting another nichrome wire of the same thickness but twice the length $(2L)$, what changes are observed in the ammeter reading?
$(ii)$ State the changes that are observed in the ammeter reading if we double the area of cross-section without changing the length in the above experiment. Justify your answer in both cases.
$(b)$ "Potential difference between points $A$ and $B$ in an electric field is $1\, V$." Explain the statement.

The unit $Joule/second$ $(J/s)$ is the unit of which of the following?

How many microamperes $(\mu A)$ are equal to $1$ milliampere $(mA)$?