RESISTANCE BOXES -DIAL TYPE CONSTANTAN & MANGANIN COIL

Dial Type Resistance Box for Physics Laboratory

The Resistance Boxes – Dial Type, Constantan & Manganin Coil from AGN Enterprises is a precision electrical laboratory apparatus used to introduce known and adjustable resistance into an electrical circuit. It is particularly useful for experiments involving Ohm’s law, electrical resistance, Wheatstone bridge measurements, circuit analysis, and resistance comparison.

The resistance box uses resistance coils made from constantan and manganin, alloys known for their useful electrical resistance characteristics and relatively low temperature coefficient compared with many ordinary metals. The dial-type arrangement allows the user to select the required resistance value conveniently through calibrated controls.

• Switching Mechanism: Equipped with latest design switches ensuring low contact resistance.
• Durable Contacts: Moving contacts made of phosphor-bronze laminations for long life and repeatability.
• Multiple Settings: Eleven-position switches allow accurate decade resistance adjustments.
• Panel Design: High-quality bakelite insulating panel, enclosed in a polished teak wood box.
• Resistance Coils:
  • Non-inductively wound, varnished, and aged for permanent value stability.
  • Available with double silk-covered Constantan wire (Grade B) or Manganin wire (Grade A).
• Temperature Stability: Manganin coils offer negligible temperature coefficient compared to copper, ensuring superior performance.
• Accuracy:
  • Constantan (Grade B): ±0.05% to ±0.1%
  • Manganin (Grade A): ±0.02% to ±0.05

Applications of Dial Type Resistance Box

The apparatus can be used for:

• Ohm’s law experiments
• Resistance measurement
• Wheatstone bridge experiments
• Meter bridge experiments
• Resistance comparison
• Circuit analysis
• Verification of electrical relationships
• Physics practicals
• Electrical laboratory demonstrations
• Student training in electrical measurements

Furthermore, it can be used with galvanometers, ammeters, voltmeters, power supplies, bridges, and other compatible electrical laboratory equipment.

Advantages of Dial Type Design

The dial-type configuration provides a convenient method for selecting resistance values. Instead of repeatedly replacing individual resistors, users can change the resistance setting directly using the calibrated controls.

Consequently, students can perform systematic experiments in which resistance is varied while other circuit parameters are observed.

The arrangement is particularly useful for demonstrating how resistance influences current and voltage in a controlled electrical circuit.

Educational Applications

The Resistance Box is an important teaching aid for physics and electrical science laboratories. Students can use it to understand practical concepts such as:

• Resistance
• Current
• Voltage
• Conductivity
• Circuit behavior
• Series and parallel resistance
• Electrical measurement
• Experimental error

It also helps students develop practical skills in circuit connection, instrument reading, data recording, and analysis.

Suitable for Schools, Colleges and Research Laboratories

The Resistance Boxes – Dial Type, Constantan & Manganin Coil are suitable for schools, colleges, universities, engineering institutions, physics laboratories, electrical laboratories, and research facilities.

Before purchasing, laboratories should confirm the required resistance range, individual step values, accuracy/class, number of dials, maximum current, terminal arrangement, and physical construction.

Why Choose Resistance Boxes from AGN Enterprises?

AGN Enterprises supplies laboratory equipment for educational, scientific, and institutional applications. This dial-type resistance box provides a practical and convenient method for introducing known resistance into experimental electrical circuits.

It is especially useful where students need to vary resistance systematically and observe the resulting changes in circuit behavior.