NDA2023General AbilityGeneral ScienceActual
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 :
Options
- A1 and 2
- Bl and 3
- C2 and 3
- D2 and 4
Correct answer
C. 2 and 3
Step-by-step solution
Resistance isinversely proportional to crosssectional area but resistivity does not depend on area of cross-section as it has constant area of 1m2. Resistance of a wire is directly proportional to length of wire whereas resistivity does not depend on length of wire because length of wire is kept constant, i.e. 1m.