Choose the correct alternative:
(a) Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
(b) Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
(c) The resistivity of the alloy manganin is nearly independent of/increases rapidly with increase of temperature.
(d) The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (1022/103).
Two wires of equal length, one of aluminium and the other of copper have the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables. (ρAl = 2.63 × 10−8 Ω m, ρCu = 1.72 × 10−8 Ω m, Relative density of Al = 2.7, of Cu = 8.9.)
A negligibly small current is passed through a wire of length 15 m and uniform cross-section 6.0 × 10−7m2, and its resistance is measured to be 5.0 Ω. What is the resistivity of the material at the temperature of the experiment?
At room temperature (27.0 °C) the resistance of a heating element is 100 Ω. What is the temperature of the element if the resistance is found to be 117 Ω, given that the temperature coefficient of the material of the resistor is `1.70xx10^-4 C^-1`
- Carbon resistors and combination of Resistance
undefined video tutorial00:55:37
- 29 Years NEET-AIPMT Chapterwise Solutions - Physics
- NEET/ AIPMT Physics - 4th Edition (Must for AIIMS & other Medical Entrance Exams)
- Marvel Physics - Multiple choice questions Vol - 1, For NEET (UG) / JEE (MAIN) Exams
- NEET MBBS / BDS Physics, Chemistry, Biology (3 in 1) Study Material & Previous years Solved Papers
- 29 Years NEET/AIPMT Topic wise Solved Papers PCB (1988 - 2016) Hindi
- Crack NEET/AIPMT Physics/Chemistry/Biology - Set of 3 Books (Must for AIIMS & Other Medical Entrance Exams)
- Topic wise Solved papers for Medical Entrance 2nd Edition (Kerala PMT/ AIPMT/ AIIMS/ JIPMER)