KVPY Government Jobs Exams

A radioactive nucleus A has a single decay mode with half life τA. Another radioactive nucleus B has two decay
modes 1 and 2. If decay mode 2 were absent, the half life of B would have been τA/2. If decay mode 1 were absent,
the half life of B would have been 3τA, then the ratio τB/τA is

Read Solution (Total 0)

KVPY Other Question

A small asteroid is orbiting around the sun in a circular orbit of radius r0 with speed V0. A rocket is launched from
the asteroid with speed V = αV0 , where V is the speed relative to the sun. The highest value of α for which the
rocket will remain bound to the solar system is (ignoring gravity due to the asteroid and effects of other planets A stream of photons having energy 3 eV each impinges on a potassium surface. The work function of potassium is
2.3 eV. The emerging photo-electrons are slowed down by a copper plate placed 5 mm away. If the potential
difference between the two metal plates is 1 V, the maximum distance the electrons can move away from the
potassium surface before being turned back is