MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

Germanium (Ge) is a Group 14 element. To form an n-type semiconductor, it must be doped with a pentavalent impurity, which is an element from Group 15 of the periodic table. Among the given options, Boron (B), Indium (In), and Gallium (Ga) are Group 13 elements (trivalent impurities) and will form p-type semiconductors when doped with Germanium. Phosphorus (P) is a Group 15 element (pentavalent impurity). When Germanium is doped with Phosphorus, it provides an extra electron, resulting in an n-type semiconductor. Answer: P