BARC EXAM 2024 MEMORY BASED QUESTIONS 1) The radiogenic heat produced by 1 kg of rock is maximum for a) Granite b) Gabbro c) Granodiorite d) Peridotite Ans : Radioactive elements are rich in continental crust and their abundance decreases downwards. The radiogenic heat produced by a rock depends on its content of radioactive elements, primarily uranium (U), thorium (Th), and potassium (K) . Among the given options: Granite ia a felsic intrusive igneous rock which has composition of Quartz and K-feldspar, K-feldspar is rich is potassium which is a radioactive element. Gabbro is a mafic rock with lower concentrations of radioactive elements having composition of Plagioclase and CPX Peridotite is ultramafic and has the least amount of radioactive elements mainly rich in Olivine. Since granite generally has the highest concentration of radioactive elements, it produces the most radiogenic heat. 2) The geoid can be best defined as a) An oblate ...
