If radius of the $$\matrix{ {27} \cr {13} \cr } $$ $$Al$$ nucleus is estimated to be $$3.6$$ fermi then the radius of $$\matrix{ {125} \cr {52} \cr } \,Te$$ nucleus is estimated to be nearly

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than $$2480$$ $$nm$$ is incident on it. The band gap in $$(eV)$$ for the semiconductor is

The intensity of gamma radiation from a given source is $$L$$. On passing through $$36$$ $$mm$$ of lead, it is reduced to $${{\rm I} \over 8}.$$ The thickness of lead which will reduce the intensity to $${{\rm I} \over 2}$$ will be

If the kinetic energy of a free electron doubles, it's deBroglie wavelength changes by the factor