1). A current of $(25 \\mu A)$ passes through a wire for 4 min . Charge flown through the wire is
2). X bivalent negative ions flow, through an electrolyte to the right, per sec and Y monovalent positive ions flow to the left per sec. The current through the electrolyte is
3). $(10^{16})$ doubly charged positive sodium ions cross any cross-section of an electrolyte per sec, to the left. The current through the electrolyte is
4). In hydrogen atom, the electron makes $(6.6 \\times 10^{15})$ revolutions per second around the nucleus in an orbit of radius $(0.5 \\times 10^{-10} m)$. It is equivalent to a current nearly