If $1 \text{ ampere}$ electric current passes through a conductor,how many electrons will pass per second?

$A$ current of $0.5\, A$ is drawn by a filament of an electric bulb for $10$ minutes. Find the amount of electric charge that flows through the circuit. (in $C$)

$100 \, J$ of heat is produced each second in a $4 \, \Omega$ resistance. Find the potential difference across the resistor. (in $, V$)

$A$ potential difference $V$ is applied across a conductor of length $L$ and diameter $D$. How is the resistance $R$ of the conductor affected,when in turn $(i)$ $V$ is halved,$(ii)$ $L$ is halved,and $(iii)$ $D$ is doubled? Justify your answer in each case.

The resistivity of semiconductor materials is $..........$.

In the given circuit,calculate $(i)$ total resistance of the circuit,and (ii) current shown by the ammeter.