Free Electrical Properties of Solids MCQs with Answers
32 Electrical Properties of Solids MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrical properties of solids depend on their band structure, charge carriers and conductivity. The topic compares conductors, insulators and semiconductors, relates resistivity to temperature, and covers intrinsic and extrinsic semiconductors, donor and acceptor impurities, electron and hole conduction, and the formation of p-type and n-type materials.
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32 questions · page 4 of 4
31. The resistance of light dependant resistance LDR:
- A. Increases with light
- B. Decreases with light
- C. Decreases with darkness
- D. None of the above
Explanation: The correct answer is that the resistance of a Light Dependent Resistor (LDR) decreases with an increase in light intensity. This is because LDRs are designed to be sensitive to light, thus reducing their resistance as they are exposed to more light. Option A is incorrect because it states the opposite of what actually happens. Option C is misleading as it incorrectly suggests that resistance decreases in darkness, whereas it actually increases. Option D is incorrect as there is a correct statement among the options provided.
Correct answer: Decreases with light32. Semi-conductor materials have:
- A. Ionic bond
- B. Covalent bond
- C. Mutual bond
- D. Metallic bond
Explanation: A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. Semiconductor materials have covalent bonding between atoms (FACT). They are only able to conduct electricity due to delocalized electrons.
Correct answer: Covalent bond