The units of resistance are ampere.

$A$ torch bulb is rated $5\,V$ and $500\,mA$. Calculate its $(i)$ power,$(ii)$ resistance,and $(iii)$ energy consumed when it is lighted for $4$ hours.

What is the resistance of an electric arc lamp,if the lamp uses $20\, A$ when connected to a $220\, V$ line?

The potential difference across a conductor is doubled,the rate of generation of heat will

What do you mean by the heating effect of electric current? Explain the production of heat in a resistor by the flow of electric current through it. Name two devices based on the heating effect of current.

Write the $SI$ unit of resistivity.