Post Office Box (PO Box) for Physics Practical Class & Exam

Plug-in type. The heavy brass contact blocks are bond to the vulcanite plated by a double nut system. The plugs & lugs are cut to a finer taper & are interchangeable. The plug heads are machine molded of bakelite. Each resistor is independently mounted with double leads. Accuracy of Constantan coils 0.1% or lower values & 0.5% for higher values. Resistor: the best-imported constant wire is wound on ebonite spools; the method adopted is non-inductive & non-magnetic. Each resistor is dipped in boiling hot wax. Provided as above with 3 ratio coils of 1000, 100 & 10 ohms. Rheostat arm 15,000 ohms. Two tapping keys with silver contacts provided for battery & galvanometer in teakwood case with hinged lid. Overall dimensions : 280x200x175mm approx.