Final answer:
The question involves using Kirchhoff's junction and loop rules to find currents in a circuit, power supplied by voltage sources, and power dissipated by resistors, which is a common problem in high school physics involving electric circuits.
Step-by-step explanation:
The student question relates to solving circuits using Kirchhoff's rules. Specifically, the question parts are regarding the calculation of current in various branches of a circuit (I1, I2, I3, etc.), the power supplied by voltage sources, and the power dissipated by resistors. When applying Kirchhoff's junction rule, it states that the total current entering a junction must equal the total current leaving, leading to an equation based on the currents at point A. Kirchhoff's loop rule states that the sum of voltage drops in a closed loop is equal to the sum of the EMFs in that loop, which helps to calculate currents when given resistances and EMF values.
For solving these problems, one would typically use the given resistance values, voltage (EMF) values, and apply the Kirchhoff's rules to set up systems of linear equations that can then be solved simultaneously.