The unit of radiation exposure is 

Key Points

• The unit of radiation exposure is measured in roentgen, which is a unit of measurement for ionizing radiation.
• The roentgen is used to quantify the amount of ionizing radiation that produces 1 electrostatic unit of charge in 1 cubic centimetre of dry air.
• This unit is named after the German physicist Wilhelm Röntgen, who discovered X-rays.
• Roentgen measures the exposure of radiation but does not directly measure the absorbed dose or biological effect, which is measured in other units like rad or sievert.
• It is primarily used in the context of X-ray and gamma-ray radiation.

Additional Information

• Candela is the unit of luminous intensity in a given direction, used in photometry.
• Dioptre is the unit of measurement for the optical power of a lens or curved mirror.
• Kelvin is the base unit of temperature in the International System of Units (SI).