V-I graph for four materials A, B, C \& D are shown in fig. The best material to make live wire of domestic wiring is :
The current in $7.2 \, \Omega$ resistor is :
The reading of the voltmeter is :
Calculate total current flowing through the circuit if \(R_1 = 7.2 \, \Omega\), \(R_2 = 8 \, \Omega\) and \(R_3 = 12 \, \Omega\) :