GATE Questions Radioactivity Method

GATE 2020

1. . Nuclide A decays to nuclide B exclusively through \(\alpha\) and \(\beta\) decay, such that the mass number is reduced by 32 and the atomic number is reduced by 10. The number of  \(\beta\) particles emitted during the decay of Nuclide A to nuclide B is .

2. The half- life of a parent radionuclide is 100yrs. If the parent radionuclide decays to daughter radionuclide which itself decays with a decay constant of \((1/4)^{th}\) that of the parents radionuclide, then radioactive equilibrium will be reached after years. (Round off to 2 decimal places). (Assume at time t = 0 the number of daughter radionuclide is zero)

GATE 2019

1. The abundance of \(^{234}U\) in secular equilibrium with its parent \(^{238}U\) will be   \(\times 10^{-3}\) %. (Given Half-life (\(T_{1/2}\) of \(^{238}U\)  and \(^{235}U\) are 4.467 × 109 y and 2.44 × 105 y, respectively, and abundance of \(^{238}U\) is 99.28%)(round off to 2 decimal places).

GATE 2018

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2017

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2016

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2015

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2014

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2013

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2012

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2011

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2010

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .

GATE 2009

1. The ratio of the number of daughter nuclides to the number of parent nuclides after a decay period of 3 half-lives is .