Question

{"given":"Four statements about semiconductors are given. Identify the one that is NOT true.","key_observation":"In an n-type semiconductor, pentavalent dopants donate free electrons, making electrons the majority carriers and holes the minority carriers — NOT the other way around.","option_analysis":[{"label":"(A)","text":"The resistance of an intrinsic semiconductor decreases with increase in temperature.","verdict":"incorrect","explanation":"This statement is TRUE. Intrinsic semiconductors have a negative temperature coefficient of resistance; as temperature rises, more electron-hole pairs are generated, increasing conductivity and decreasing resistance."},{"label":"(B)","text":"Doping pure Si with trivalent impurities gives p-type semiconductors.","verdict":"incorrect","explanation":"This statement is TRUE. Trivalent impurities (e.g., boron, aluminium) have one fewer valence electron than Si, creating holes and producing p-type semiconductors."},{"label":"(C)","text":"The majority carriers in n-type semiconductors are holes.","verdict":"correct","explanation":"This statement is FALSE and hence the answer. In n-type semiconductors, pentavalent dopants donate extra electrons, so electrons are the majority carriers and holes are the minority carriers."},{"label":"(D)","text":"A p-n junction can act as a semiconductor diode.","verdict":"incorrect","explanation":"This statement is TRUE. A p-n junction allows current to flow preferentially in one direction (forward bias) and blocks it in reverse bias, functioning as a diode."}],"answer":"(C)","formula_steps":[]}