Post Office Box (PO Box) for Physics Practical

Post Office Box (Wheatstone Bridge) – Physics Lab Equipment | Premium Quality | Made in India

The Post Office Box (PO Box) is a compact and precise version of the Wheatstone Bridge, used for measuring unknown electrical resistance in physics laboratory experiments. It is widely used in physics practical classes, exams, and research laboratories for demonstrating the principle of Wheatstone’s bridge with high accuracy.

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🔧 Key Specifications & Features

• Type: Plug-in Wheatstone Bridge Resistance Box

• Arms:

  • P & Q: Ratio arms (1000Ω, 100Ω, 10Ω)

  • R: Rheostat arm (15,000Ω)

  • X: Unknown resistance (to be measured)

• Construction:

  • High-quality bakelite molded plug heads

  • Heavy brass contact blocks with double nut bonding

  • Constantan resistance wire, non-inductive & non-magnetic

  • Precision accuracy: ±0.1% (low values), ±0.5% (high values)

  • Resistors dipped in boiling wax for long life and stability

• Dimensions: 280 × 200 × 175 mm (approx.)

• Case: Premium teakwood with hinged protective lid

• Origin: Made in India

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📘 Applications

• Measuring unknown resistance using Wheatstone Bridge method

• Physics practical classes & lab examinations

• Demonstration of Ohm’s Law & bridge circuits

• Research and calibration work in educational institutions

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✅ Why Choose This PO Box?

• Premium build quality for long-lasting lab use

• Highly accurate & reliable resistance measurements

• Smooth plug-in design with interchangeable precision plugs

• Ideal for schools, colleges, universities, and training centers