A plug-type resistance box with a 50-ohm resistance is a precision instrument commonly used in educational, laboratory, and industrial settings for measuring and adjusting resistance in electrical circuits. Here are the full details you might expect:

1. Type: Plug-type resistance box. This type uses removable plugs to change the resistance values, allowing for easy adjustment and precise control of the resistance.
2. Resistance Range: This specific box provides resistance values up to 50 ohms. Plug-type resistance boxes typically have multiple resistors arranged in a manner that allows for various combinations to achieve different resistance values.
3. Construction:
   • Body: Typically made from robust materials such as Bakelite, phenolic, or other high-quality plastics to ensure durability and electrical insulation.
   • Resistors: High-precision wire-wound resistors or carbon composition resistors are used, which are accurately calibrated to provide reliable and consistent resistance values.
   • Plugs: Metal plugs, often brass or another conductive metal, are used to insert or remove from terminals to adjust the resistance.
   • Terminals: Made from brass or similar conductive materials, often nickel-plated to resist corrosion and ensure good electrical contact.
4. Accuracy: Resistance boxes are designed to offer high accuracy, typically within ±1% or better, depending on the quality of the box. This ensures precise control over the resistance values.
5. Operation:
   • Plugs: By inserting or removing plugs into the designated terminals, the user can change the resistance value. Each plug corresponds to a specific resistance, and combining different plugs allows for a wide range of resistance values.
   • Terminals: The box will have at least two terminals for connecting to the circuit. The resistance between these terminals is adjusted by manipulating the plugs.
6. Applications:
   • Educational: Used in physics and electrical engineering labs to demonstrate principles of resistance, Ohm’s law, and other electrical properties.
   • Calibration: Employed in the calibration of other electrical instruments and devices to ensure their accuracy.
   • Experimental: Utilized in various experimental setups requiring precise resistance adjustments.
7. Maintenance:
   • Cleaning: Regular cleaning of the plugs and terminals is necessary to maintain good electrical contact and accurate resistance values.
   • Calibration: Periodic calibration checks are recommended to ensure the resistors maintain their accuracy over time.
8. Accessories: Depending on the manufacturer, the resistance box may come with additional accessories such as spare plugs, a carrying case, and a calibration certificate.
9. Manufacturer: The specific details about the manufacturer may vary, but reputable brands known for producing high-quality laboratory instruments are preferred for such precise equipment.
10. User Manual: A detailed user manual is provided, offering instructions on operation, calibration, maintenance, and troubleshooting. This ensures users can effectively and safely use the resistance box.
11. Specifications:
    • Maximum Resistance: 50 ohms.
    • Resolution: The smallest change in resistance that can be achieved by inserting or removing a plug.
    • Material of Resistors: Typically, manganin or nichrome wire for wire-wound resistors, known for their stable resistance over a range of temperatures.
    • Dimensions and Weight: Varies by manufacturer but generally compact and lightweight for ease of use and portability.

In summary, a plug-type resistance box with 50-ohm resistors is a versatile and precise tool essential for various educational, calibration, and experimental applications. Its construction ensures durability and accuracy, making it a valuable instrument in any laboratory setting.