84. The film projection lamp, rated at 110 V and current 3 A is connected to a network with a voltage of 127 V through a resistor. To determine the resistance of the rheostat, if it is known that the voltage drop in the conductive copper wire is 2% of the voltage at cross-section of 1.8 mm2? Rheostat inserted fully.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)