Multi-Loop Circuit

Instructions
This simulation applies Kirchoff's circuit rules to a multi-loop circuit with three branches. The resistance of each resistor and the emf of each battery can be changed using the sliders. Set a resistance or emf to zero to remove it from the circuit. Positive emf represents a battery with positive terminal upwards, while negative emf represents positive terminal downwards.[br][br]The initial guess for the direction of each current can be selected from the drop-down list. Similarly, drop down lists are used to select where to apply Kirchoff's rules.
[list=1][*]What effect does changing the initial guess for the direction of a current have on the final solution?[/*][*]What effect does changing a loop direction have on the produced equation?[/*][*]Some combinations of resistance and emf result in an infinite or undefined current. Why?[/*][*]Can you find a combination of values that results in zero current throughout the entire circuit (with at least one nonzero emf)?[br][/*][/list]

Information: Multi-Loop Circuit