Question

Answer the following questions :

1. What is meant by the statement " The potential difference between two points is 1 V ? "

2. On what factors does the resistivity of a wire depend on ?

3. Two metallic wires of iron and copper are of the same length and same radius. Which will have more resistance ?

4. A wire X is stretched to double its length. What is the new resistivity ?

5. Which will have higher resistivity – a conductor or an insulator ?

6. How does the resistance change with the temperature in a conductor ?

7. A wire is stretched to twice its original length. Does its resistance change ? If yes, then by what factor ?

8. Write an expression for the resistance of a conductivity wire in terms of length and area of cross - section.

9. Which of the two conducting wires of 3 ohm and 11 ohm is thicker ?

10. Define resistivity of the cell.

Answer 1

1. when 1 joule of work is done to move 1 coulomb of eletric charge from one point to another, it is said to be 1 volt.
2.the resistivity of a wire depends on length of the wire, area of cross section and nature of the material used.
3.
4. the resistivity will be doubled.
5.insulator
6.
7. the resistance will be doubled because resistance is directly proportional yo length.
8. R is directly proportional to L and inversely proportional to A .
R = rho L/A
10.