In the circuit of figure, when switch S1 is closed, the ideal ammeter M₁ reads 5A. What will be ideal voltmeter M₂ read when S₁ is kept open? (The value of E is not specified).

In the following circuit the capacitance varies as C = KQ, where K is a constant equal to 0.5 Farads/Coulomb and Q, the charge on the capacitor in Coulombs. Determine the current through the circuit and sketch the voltage waveform across the capacitor (V_C) for a step input V_i as shown in figure.

An infinite grid is built up by connecting resistors in the manner indicated in figure, where each branch represents one ohm resistor. Calculate the effective resistance between the nodes A and B.

In figure, A₁, A₂ and A₃ are ideal ammeters. If A₁ reads 5 A, A₂, A₂ reads 12 A, then A₃ should read