Physics questions with answers

2,629 multiple-choice questions. Open any question for its answer and explanation.

Questions asked in State PSC and UPSC prelims, by topic. Each topic also has notes to read.

Read the notes: Conductivity →

1. Which one of the following is not a semiconductor?Asked in UPSC CDS 1 2017
2. Which one of the following is an electric conductor ?Asked in UPSC CDS 1 2021
3. Which one of the following semi-conductors possesses the highest value of band gap Eg?Asked in UPSC Geoscientist 2023
4. Consider the following : (a) Mica (b) Graphite (c) Sulphur (d) Human body Which among the above is/are electrical conductors?Asked in KPSC KAS Prelims 2024
5. Which one of the following statements is correct with regard to the material of electrical insulators ?Asked in UPSC NDA 1 2017
6. The substance which has a large number of free electrons and offer a low resistance is called :Asked in UKPSC CS Prelims 2021
7. What is the correct sequence of conductivity when arranged in ascending order?Asked in UPSC CAPF 2013
8. Which of the following elements is a semiconductor?Asked in WBCS Main Paper 4 2021
9. Consider the following statements and choose the correct ones using the codes given below : A. Graphite is good conductor of heat & electricity. B. Graphite is good conductor of heat but an electrical insulator. C. Diamond is good conductor of heat but an electrical insulator. D. Diamond is bad conductor of heat & electricity. Codes :Asked in ACF And Forest Range Officer Gr I Comp. Exam 2018
10. Which of the following allow the electric current to pass through it : A) Glasses B) Graphite C) Rubber D) PVCAsked in ASSISTANT AUDIT OFFICER 2017 18 2017
11. A solar cell unit is basically a :Asked in Assistant Engineer (AE) Exam 2013
12. Non-metals are generally bad conductor of electricity. However, among the following non- metals, which is/are good conductor(s)? I. Sulphur II. Fluorine III. Diamond IV. Graphite Choose the correct answer from the following :Asked in ARO GS 252022 74 2024
13. The colour of light emitted by a Light Emitting Diode (LED) depends onAsked in Co operative Supervisor & Environment Supervisor (Group C) Exam 2023
14. When a forward bias is applied to a p-n junction, itAsked in Co operative Supervisor & Environment Supervisor (Group C) Exam 2023
15. Which of the following is not an insulator?Asked in J.E (Electrical 2020) 2020
16. Most commonly used semi-conductive material is :Asked in Regional Inspector (Technical) Exam 2022
17. Which one of the following is primarily responsible for conduction of current in a metal ?Asked in UPSC NDA 1 2024
18. Which one among the following is the correct representation of the electric field when a conducting spherical shell is placed between the plates of a parallel plate capacitor ?Asked in UPSC Geoscientist 2024
19. An ebonite plate (K = 3), 6 mm thick, is introduced between the parallel plates of a capacitor of plate area 2 × 10⁻² m² and plate separation is 0.01 m. The capacitance of the capacitor would be (ε₀ = 8.85 × 10⁻¹² F/m)Asked in Co operative Supervisor & Environment Supervisor (Group C) Exam 2023
20. A parallel-plate capacitor of capacitance C₁ is made using two gold plates. Another parallel- plate capacitor of capacitance C₂ is made using two aluminium plates with same plate separation, and all the four plates are of same area. If ρg and ρa are respectively resistivities of gold and aluminium, then which one of the following relations is correct?Asked in UPSC CDS 1 2017
21. Two metallic wires made from copper have same length but the radius of wire 1 is half of that of wire 2. The resistance of wire 1 is R. If both the wires are joined together in series, the total resistance becomesAsked in UPSC CDS 1 2018
22. We are given three copper wires of different lengths and different areas of cross-section. Which one of the following would have highest resistivity ?Asked in UPSC CDS 1 2021
23. What is the correct sequence of resistivity of silver, nichrome and glass at room temperature ?Asked in UPSC CDS 1 2022
24. Two wires are made having same length l and area of cross-section A. Wire 1 is made of copper and wire 2 is made of aluminium. It is given that the electrical conductivity of copper is more than that of aluminium. In this context, which one of the following statements is correct?Asked in UPSC CDS 2 2017
25. A metal wire of length l and diameter d has a resistance R. What would be the resistance of another wire of the same metal and of same length but having double the diameter ?Asked in UPSC CDS 2 2022