The circuit that follows is for a laboratory potentiometer
for measuring unknown voltages Vx.
Assume the resistor AB is a slide wire whose resistance is
directly proportional to its length. With the standard Weston cell (1.018 V) in
the circuit, a null point was observed when contact C was moved to a position
84.3 cm from point A. When the Weston cell was replaced with a cell of an
unknown voltage Vx, null was observed at 44.3 cm. Find the value of