Get premium membership and access revision papers with marking schemes, video lessons and live classes.
Processing. Please wait.

 Form 4 Physics online video lessons on X-Rays

Meaning and how X-rays are produced

 (5m 56s)
211 Views     SHARE

Download as pdf file

Answer Text:
X-rays were discovered by a German scientist named Roentgen in 1985. They can pass through most substances including soft tissues of the body but not through bones and most metals. They were named X-rays meaning 'unknown rays'.
X-ray production
They are produced by modified discharge tubes called X-ray tubes. The cathode is in the form of a filament which emits electrons on heating. The anode is made of solid copper molybdenum and is called the target. A high potential difference between the anode and the cathode is maintained (10,000 v to
1,000,000 or more) by an external source. The filament is made up of tungsten and coiled to provide high resistance to the current. The electrons produced are changed into x-rays on hitting the anode and getting stopped. Only 0.2% of the energy is converted into x-rays. Cooling oil is led in and out of the hollow
of the anode to maintain low temperature. The lead shield absorbs stray x-rays.