Resistance Box Plug Type (Constantan / Manganin Coil)
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Product Code : LSK-EAE-11110
Resistance Box Plug Type (Constantan / Manganin Coil) (SKU LSK-EAE-11110) is a plug-key resistance box: non-inductive coils sit beneath a thick rectangular brass block, and removing a brass plug adds that coil to the circuit. It is offered with constantan coils or, for tighter accuracy, manganin coils, for bridge and potentiometer practicals in school, college and university labs. Science Lab Supplies manufactures the box at Plot 448, HSIIDC Industrial Area, Saha, Ambala, India, and sells it directly to schools, colleges, tender contractors and distributors.
Specifications
Each specification is listed in the table below. In summary, the coils are double covered constantan wire wound non-inductively on bakelite spools, connected to a 10 or 12 mm thick brass block and housed in a wooden box; accuracy is ±0.05% to ±0.1% with constantan or ±0.02% to ±0.05% with manganin coils.
| Specification | Value |
|---|---|
| SKU | LSK-EAE-11110 |
| Type | Plug-type resistance box |
| Coil options | Constantan coil or manganin coil |
| Accuracy, constantan coil | ±0.05% to ±0.1% |
| Accuracy, manganin coil | ±0.02% to ±0.05% |
| Coil wire | Double covered constantan wire |
| Winding | Non-inductive |
| Coil former | Bakelite spool |
| Brass block | Rectangular, 12 mm or 10 mm thick (approx. 1/2 inch) |
| Enclosure | Wooden box |
| Body | Anti-corrosive |
| Resistance values | Stated on the quotation for the box ordered |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Plug Type Resistance Box
A plug box supplies accurately known resistances that students select by pulling plugs, so it serves as the known arm or series resistance in many electrical practicals. Its non-inductive coils and solid brass block keep contact resistance low, which makes it core physics lab equipment in India for Class 12 and degree courses.
- Class 12 physics: known resistance in meter bridge experiments and in finding the resistance of a galvanometer by half-deflection, read on a Galvanometer.
- Potentiometer experiments: comparing emfs and measuring internal resistance of a cell.
- Ohm's law and series-parallel circuits, switched with a Brass One Way Plug Key.
- B.Sc. labs: conversion of a galvanometer into an ammeter or voltmeter.
Seat each plug firmly with a slight twist and keep plugs and sockets clean, since dirt adds contact resistance.
Standard Scope of Supply
The Resistance Box Plug Type (Constantan / Manganin Coil) is supplied as a single unit as described above, in its wooden box with the brass block and plugs. Choose constantan or manganin coils when enquiring; the coil values and any optional accessories are listed on the quotation.
Packing, MOQ and Lead Time
You can request a quotation for one resistance box or for a full set for an electricity laboratory. Each Science Lab Supplies quotation states packing, delivery time and price for that quantity, and bridges, galvanometers or plug keys can appear on the same quote.
Science Lab Supplies, an exporter with an Importer-Exporter Code, can ship to buyers in Nigeria, Kenya, Ghana, Ethiopia, Tanzania and Uganda. Send an enquiry through the contact page or the enquiry cart; for tenders, read the lab tender page.
Frequently Asked Questions
What is the difference between the constantan and manganin coil versions?
Both use the same plug-type construction. The constantan coil version is accurate to ±0.05% to ±0.1%, while the manganin coil version offers tighter accuracy of ±0.02% to ±0.05%.
How is a resistance selected on a plug box?
Each coil is bridged by a brass plug. Removing a plug forces the current through that coil, so the total resistance in circuit is the sum of the coils whose plugs have been taken out.
Which resistance values are available?
The coil values and total range depend on the box configuration ordered. Tell us the values your experiments need through the contact page, and the quotation will list the coils for the box offered.
Is Science Lab Supplies the manufacturer or a trader?
Science Lab Supplies is the manufacturer: the box is wound, assembled and finished at its Ambala-district factory in Saha, India. Your quotation therefore comes from the people who build it, with no trader in the chain.
Related Resistance Boxes and Bridge Apparatus
These resistance boxes, bridges and standards from the Electrical and Electronics, Applied Mechanics and physics ranges serve the same bridge, potentiometer and Ohm's law practicals, so a teacher can compare box types and equip a full electricity bench on one quotation.
- Decade Resistance Box, Dial Type — high-stability 1% metal film decades in two, three or four dials.
- Resistance Substitution Box — 10 Ω to 1 MΩ in 24 steps, 5% tolerance, 1/2 W.
- Post Office Box Plug Type — 3- or 4-ratio P.O. box with sixteen coils and two spring keys.
- Resistance Box Electronic Type — versions of 50, 100, 500 and 1000 Ω.
- Resistance Box — 3- to 6-dial decade box with 1 W per step and 4 mm terminals.
- Meter Bridge or Wheatstone Bridge With Pencil Jockey — four-gap copper-strip bridge with 24 SWG constantan wire.
- Potentiometer with Jockey Pencil — wooden base with brass blocks and a 100 cm scale.
- Resistance Coil 1 Ohm — non-inductive manganin 1 Ω coil, ±1%.
Browse the full Electrical and Electronics range, the Lab Meters range for galvanometers and meters, or all physics lab equipment.
Last updated: 9 October 2026
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