Kirchhoff's first law i.e. $\Sigma i=0$ at a junction is based on the law of conservation of :

1. Charge

2. Energy

3. Momentum

4. Angular momentum

The figure below shows currents in a part of electric circuit. The current i is

1. 1.7 amp

2. 3.7 amp

3. 1.3 amp

4. 1 amp

The figure shows a network of currents. The magnitude of currents is shown here. The current i will be 

1. 3 A

2. 13 A

3. 23 A

4. – 3 A

The current in the arm \(CD\) of the circuit will be:
             

1. \(i_{1} + i_{2}\)

2. \(i_{2} + i_{3}\)

3. \(i_{1} + i_{3}\)

4. \(i_{1} - i_{2} + i_{3}\)

Kirchhoff’s first and second laws for electrical circuits are consequences of: