The relationship between potential difference (V) and current (I) is given by Ohm's Law. Ohm's Law states that: \[ V = IR \] where:
V = Potential Difference (Volts)
I = Current (Amperes)
R = Resistance (Ohms)
This law was formulated by the German physicist Georg Simon Ohm.
The correct option is (D): Ohm
An infinitely long straight wire carrying current $I$ is bent in a planar shape as shown in the diagram. The radius of the circular part is $r$. The magnetic field at the centre $O$ of the circular loop is :
