Electrical resistivity of a given metallic wire depends upon
its length
its thickness
nature of the material
its shape
If the charge on an electron be $1.6 \times 10^{-19} C$, find the approximate number of electrons in $1 C$
A $100$ watt electric bulb is lighted for $2$ hours daily. and four $40$ watt bulbs are lighted for $4$ hours everyday. Calculate the energy consumed (in $k W h$ ) in $30$ days.
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.
The $SI$ unit of resistivity of the material is $......$
Why is very less heat generated in long electric cables than in filaments of electric bulbs ?