The formula for Ohm’s law is:
V = I × R
where:
V = Voltage (in volts),
I = Current (in amperes),
R = Resistance (in ohms).
It states that the current through a conductor between two points is directly proportional to the voltage across the two points.
In the adjoining figure, $\triangle CAB$ is a right triangle, right angled at A and $AD \perp BC$. Prove that $\triangle ADB \sim \triangle CDA$. Further, if $BC = 10$ cm and $CD = 2$ cm, find the length of AD. 