Q.(a) What are X-rays ? Mention its clinical significance. OR

X-rays are high-energy electromagnetic radiation used clinically to image internal structures like bones (radiography) and, in a controlled therapeutic form, to destroy cancerous tissue (radiotherapy).

Answering part (a): X-rays are a form of electromagnetic radiation with a very short wavelength (roughly 0.01 to 10 nanometres) and correspondingly very high energy and frequency, positioned on the electromagnetic spectrum between ultraviolet rays and gamma rays. They were discovered in 1895 by the German physicist Wilhelm Conrad Röntgen, who named them 'X-rays' because their nature was then unknown. X-rays are produced when a stream of high-speed electrons, accelerated across a high voltage inside a vacuum tube (an X-ray tube), strikes a metal target (commonly tungsten); the sudden deceleration of these electrons on impact releases energy in the form of X-ray photons. A key property that makes X-rays medically useful is differential absorption: X-rays pass relatively easily through soft tissues (muscle, fat, skin) but are strongly absorbed by denser materials, particularly calcium-rich structures like bones and teeth, which is why bones appear as clear white/light shadows on an X-ray image while soft tissue appears darker. Clinical significance: because of this property, X-rays (radiography) are widely used to diagnose fractures and dislocations of bones, dental cavities and jaw problems, chest diseases such as tuberculosis and pneumonia (which show up as opacities in the lungs), and, with the aid of contrast media, to visualise soft structures such as the kidneys or digestive tract; more advanced X-ray-based techniques like CT (computed tomography) scanning provide detailed cross-sectional images of internal organs for diagnosis. In addition to diagnosis …