Question

Electromagnetic waves against their detection devices are matched below. The mismatch is

• A. Gamma rays : Ionization chamber
• B. Infrared rays : Bolometer
• C. X-rays : Photographic film
• D. Ultraviolet rays : Thermopiles
• E. Microwaves : Point contact diode

Answer 1

Answer: (E)

Electromagnetic waves are detected using different devices depending on their properties. Let's go through the matching of each electromagnetic wave to its detection device:

• Gamma rays : Ionization chamber - Gamma rays are high-energy electromagnetic waves that can ionize atoms. An ionization chamber is used to detect them by measuring the ionization produced by the gamma rays.
• Microwaves : Point contact diode - Microwaves are detected using a point contact diode, which can measure the change in resistance when exposed to microwave radiation.
• X-rays : Photographic film - X-rays are commonly detected by exposing photographic film. The X-rays cause a change in the film's properties, which can then be analyzed.
• Ultraviolet rays : Thermopiles - Thermopiles can detect ultraviolet (UV) rays by measuring the heat generated by the absorption of UV radiation.
• Infrared rays : Bolometer - Infrared rays are detected by a bolometer, which measures the heat produced by the absorption of infrared radiation. The bolometer works by detecting changes in resistance as it absorbs infrared energy.

The mismatch in the provided options is:

• Infrared rays : Bolometer - This is the correct match, as a bolometer is designed to detect infrared radiation by measuring the temperature change caused by it. Therefore, there is no mismatch here. The other devices in the list are appropriately matched to the corresponding waves.

Correct Answer:

Correct Answer: (E) Infrared rays : Bolometer

Answer 2

- Gamma rays are typically detected using ionization chambers as they ionize the air in the chamber, allowing measurement of their intensity.  
- Microwaves are generally detected using devices such as magnetrons, bolometers, or diodes specifically designed for microwave detection. The point contact diode is not commonly used for microwave detection.  
- X-rays are detected using photographic film, as they expose the film, which can be developed to visualize the intensity of X-rays.  
- Ultraviolet rays are detected using thermopiles, which measure temperature changes due to the absorption of UV radiation.  
- Infrared rays are detected using bolometers, which measure the heat produced by infrared radiation.  

Thus, option (B) is the mismatch, as microwaves are not typically detected by point contact diodes.