Q147
General SciencePhysics
X-unit = ?
- a.10$^{-15}$m
- b.10$^{-12}$m
- c.10$^{-10}$m
- d.10$^{-13}$m
Answer: (D) 10$^{-13}$m
The X-unit, used for X-ray and gamma-ray wavelengths, is about $1.002 \times 10^{-13}$ metre. $10^{-10}$ m is the angstrom, $10^{-12}$ m the picometre and $10^{-15}$ m the fermi.