Resistance Substitution Box
Product Code : LSK-PL-10308
Resistance Substitution Box (SKU LSK-PL-10308) is a compact switched unit that lets a student dial any one of 12 fixed resistors into a circuit with a rotary switch, instead of swapping loose components. It serves Class 10–12 electricity practicals, B.Sc. and diploma electronics labs and ITI trade training. The unit is manufactured by Science Lab Supplies in its own Saha, Ambala works (Plot 448, HSIIDC Industrial Area), and quotations go straight to schools, colleges, tender contractors and distributors.
Specifications
Twelve resistors of preferred values sit on a printed circuit inside a robust black plastic box. A rotary switch selects one value at a time, and two yellow 4 mm terminals, coloured to show that the connection is non-polar, take it out to the circuit. Each resistor is rated at 1 W maximum.
| Parameter | Value |
|---|---|
| SKU | LSK-PL-10308 |
| Resistors | 12, preferred values |
| Tolerance | 5% (values can be closer to nominal) |
| Power rating | 1 W maximum per resistor |
| Selection | Rotary switch |
| Terminals | Two 4 mm, yellow (non-polar) |
| Construction | Printed circuit in a robust black plastic box |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Resistance Substitution Box
The box is used wherever a practical needs several known resistances in turn: Ohm's law readings, series and parallel checks, voltage dividers and trial values in simple electronic circuits. Turning the switch changes the value, so a full set of readings needs no rewiring.
- Class 10 physics (Electricity): current–voltage readings for different resistances.
- Class 12 physics: supplying known resistances in circuit and bridge practicals.
- ITI Electronics Mechanic trade: resistor selection and measurement exercises.
Standard Scope of Supply
The Resistance Substitution Box is supplied as a single unit as described above: the 12 resistors on their printed circuit, the rotary selector switch and the two 4 mm terminals, all housed in the black plastic box. Connecting leads and meters are separate items that can be added to the quotation.
Packing, MOQ and Lead Time
Ask for one box for a teacher's bench or enough for every student group in the electricity lab. The quotation you receive sets out packing, delivery time and price for exactly that number, and other physics lab equipment in India, such as a multimeter, can share it.
Science Lab Supplies is a registered exporter holding an Importer-Exporter Code, so it can ship to buyers in Zambia, Rwanda, South Africa, Qatar, Sri Lanka and Vietnam. The business is registered under Udyam as a manufacturing enterprise (UDYAM-HR-01-0014546) and for GST (GSTIN 06ADEPJ0574F2ZU). Send your list via the contact page or the enquiry cart; tender buyers can start from the lab tender page.
Frequently Asked Questions
How accurate are the resistor values?
The resistors have a 5% tolerance. Individual resistors can sit closer to their nominal value, so students should measure the selected resistance with a meter when a practical needs the exact figure.
Why are the terminals yellow?
The two 4 mm terminals are yellow to show that the connection is non-polar: a resistor has no positive or negative end, so the box can be connected either way round in the circuit.
Is Science Lab Supplies the manufacturer or a trader?
Science Lab Supplies is a science apparatus manufacturer in India, not a trader. The box is built in the company's Saha, Ambala factory in India, and quotations come from the maker.
How much power can each resistor take?
Every resistor in the box has a maximum power rating of 1 W. Choose the supply voltage so that the power in the selected resistor stays under that figure.
Related Electrical Measurement Equipment
These four items share the substitution box's job of setting or measuring circuit values on the bench. Together they let a class vary resistance and capacitance, control current and read the results, and all of them can be listed on one quotation.
- Capacitance Substitution Box — a similar rotary-switched box holding capacitors instead of resistors.
- Resistance Box — decade dials for setting resistance in fine steps.
- Digital Multimeter — measures voltage, current and resistance to check each setting.
- Rheostat — high-power 10 Ω rheostat for controlling current.
Browse the full Physics Lab range or all physics lab equipment.
Last updated: 25 September 2026
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