Calculate total current flowing through the circuit if \(R_1 = 7.2 \, \Omega\), \(R_2 = 8 \, \Omega\) and \(R_3 = 12 \, \Omega\) :
In the Adjoining figure, if O is the centre of the circle of radius 5cm, OP=13 cm, where PQ and PR are tangents to the circle from point P. Length PR is :