Passage I Short wavelength electromagnetic rays called X-rays are often used to

Question

Passage I Short wavelength electromagnetic rays called X-rays are often used to image internal anatomical structures. Some parts of the body are nearly transparent to X-rays, while others are relatively opaque. A picture is taken of the shadow cast under X-ray illumination. The intensity of a beam of X-rays transmitted through a medium is given by where I, is the intensity incident on the medium, is the absorption coefficient of the medium (which is dependent upon the density of the medium), and x is the distance traveled through the medium. Like other electromagnetic waves, the frequency/and the wavelength of a beam of X-rays satisfy the relations c-M and E=hf where c is the speed of light in a vacuum, E is the energy of a photon, and h is Plank's constant. (Note: h = 6.62 x 10.34 m 3kg/s, 1 eV = 1.6 x 10-19 Joules.) X-rays interact with atoms primarily via collisions with electrons in low atomic energy levels. The probability of a collision with an electron in a neutral atom is proportional to the fourth power of the nuclear charge. In this type of collision, the electron is frequently ejected from the atom. A higher level electron falls down to fill the vacancy, emitting a long wavelength photon in the process and creating a new vacancy at a higher energy level. This process continues until there are no electrons at higher energy levels to fall to a lower state, leaving a single vacancy. The atom is then singly-ionized. This rapid emission of photons is called a cascade. Geiger counters measure the intensity of X-rays by maintaining a high voltage difference between a wire and the metal wall of a gas chamber. Free electrons created by radiation-induced ionization are accelerated toward the wire so rapidly they ionize even more atoms in the gas. This ionization avalanche causes the counter to click

Explanation / Answer

Answer is C

As given in the data we can say intersity is propsnal to negative power of e, when we take ratio opf it then negative power comes up and make ans e.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.