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 →

26. Which one of the following is the most appropriate reason for aircraft being equipped with conducting tyres ?Asked in UPSC CDS 2 2024
27. The electrical resistance of a wire varies directly with its length and inversely with the square of its diameter. If a wire with a length of 200 cm and a diameter of one-quarter of a centimeter has a resistance of 20 ohms, find the electrical resistance in a 500 cm wire with the same diameterAsked in GPSC Prelims CSP 1 2018
28. The product of conductivity and resistivity of a conductorAsked in UPSC NDA 1 2015
29. Which one of the following correctly represents the SI unit of resistivity?Asked in UPSC NDA 1 2022
30. Why are the tyres of aircrafts made of conducting rubber? 1. So that the charge accumulated on the aircraft in flight, by rubbing the air, can easily be transferred to ground on landing. 2. So that the charge accumulated due to the operation of various electronic equipments in the aircraft in flight can easily be transferred to ground on landing. Select the correct answer using the code given below.Asked in UPSC NDA 1 2022
31. Which one of the following graphs correctly represents the current (I) – voltage (V) variation for a rectangular piece of a semiconductor wafer ?Asked in UPSC NDA 2 2023
32. Which of the following statements are correct about the electrical resistance and resistivity of a wire? 1. Both quantities depend on the area of cross-section of the wire 2. Both depend on the temperature 3. Resistance of the wire is directly proportional to the resistivity of the wire 4. Resistivity of the wire is directly proportional to the length of the wire Select the correct answer using the code given below :Asked in UPSC NDA 2 2023
33. The resistivity of a wire varies with itsAsked in PPSC CS Prelims 2013
34. Vehicles carrying inflammable materials usually have metallic ropes touching the ground during motion in order toAsked in UPSC CAPF 2011
35. Which one of the following is the best conductor of electricity?Asked in UPPSC Upper Mains 2015 · RPSC RAS Prelims 2012
36. The best conductor of electricity amongst the following isAsked in UPPSC Upper Mains 2012
37. Two wires have their lengths, diameters and resistivities, all in the ratio of 1: 2. If the resistance of the thinner wire is 10 ohms, the resistance of the thicker wire isAsked in UPPCS Prelims 2001
38. The best Conductor of Electricity is:Asked in APPSC Draughtman 2008
39. For a metallic wire, the ratio $\frac{V}{I}$ [V = applied potential difference and I = current flowing] isAsked in WBCS Main Paper 4 2019
40. Which among the following has maximum electrical resistivity?Asked in Asst. Engineer Comb. Comp. Exam 2018
41. Electrical resistivity of a given metallic wire depends upon :Asked in Clerk GR II Comb. Comp. Exam 2013
42. Electric press, heater, electric kettle etc. are made of which element?Asked in Civil Judge 2022
43. What is the reason behind using copper wires in domestic electrical wiring?Asked in moter vehicle inspector
44. On which of the following does the resistance of a conductor depend ?Asked in Forest Range Officer Exam 2021
45. When a piece of pure silicon is doped with aluminium, thenAsked in UPSC CDS 1 2017
46. Suitable impurities are added to a semiconductor depending on its use. This is done in order toAsked in KPSC KAS Prelims 2014
47. The majority charge carriers in a p-type semiconductor areAsked in UPSC NDA 2 2017
48. The valence electron of the impurity atom that is to be added to germanium crystal so as to make it a n-type semiconductor isAsked in TNPSC CS Prelims 2017
49. Electric conduction in a semiconductor takes place due toAsked in UKPSC CS Prelims 2016
50. In N-type semiconductor, ultrapure Si is doped withAsked in WBCS Main Paper 4 2022