Question

If 1 kg mass stretches a wire of diameter 1 mm by 0.5 mm, how far a wire of same length but twice the diameter be stretched by a mass of 8 kg ?

Answer 1

Answer:

d=0.5mm,Y=2×10  

11

,l=1m

      △l=  

Ay

Fl

​  

=  

4

πd  

2

 

​  

y

mgl

​  

=  

4

π

​  

×(5×10  

−4

)  

2

×2×10  

11

 

1.2×10×1

​  

 

△l=  

4

3.2

​  

×25×10  

−8

×2×10  

11

 

1.2×10×1

​  

 

=  

0.8×25×2×10  

3

 

12

​  

=  

40×10  

3

 

12

​  

=0.3mm

So 3rd division of vernier scale will coincide with main scale.

Explanation:

hope so it will help you