$Ohm's$ law is a relation between the power used in a circuit to the current and the potential difference.

What is the resistance of an ideal ammeter?

Calculate the resistance of an electric bulb which allows a $10 \ A$ current when connected to a $220 \ V$ power source. (in $\Omega$)

You are given three bulbs of $25 \, W$,$40 \, W$,and $60 \, W$ marked at $220 \, V$. Which one of them has the lowest resistance?

The $SI$ unit of resistivity of the material is $......$

Describe the nature of the $V-I$ graph for a nichrome wire. ($V =$ Potential difference,$I =$ Current)
$A$ metallic wire of $625 \, mm$ length offers a $4 \, \Omega$ resistance. If the resistivity of the metal is $4.8 \times 10^{-7} \, \Omega \cdot m$,calculate the cross-sectional area of the wire.