Question

Items amenable to detection by soft X-rays are:

• A. Contrabands
• B. Lead in bullets
• C. Narcotics
• D. Genuine coins from counterfeit coins

Hint:

Soft X-rays have low penetration, useful for fine detail in thin dense objects like coins.

Answer 1

The Correct Option is D

Step 1: Soft X-rays are X-rays of relatively low energy and longer wavelength compared to hard X-rays. Because of their lower energy, they are absorbed more easily and cannot penetrate very thick or very dense materials.

Step 2: This low penetrating power is useful for examining objects that are thin and made of dense metal, where small differences in internal composition or structure need to show up clearly on the image.

Step 3: Genuine coins are minted from metal of a fixed, uniform composition and density, while counterfeit coins are usually made from different alloys or have small internal differences to save cost. Soft X-ray imaging can reveal these subtle density or composition differences between a genuine coin and a fake one.

Step 4: Detecting contraband, narcotics, or lead in bullets buried in luggage or tissue generally needs X-rays with more penetrating power to pass through thick, mixed material, which is more the domain of harder X-rays or other techniques, not the fine, low penetration soft X-ray examination described here.

Answer: Soft X-rays are used to distinguish genuine coins from counterfeit coins, option D.