12) When a screw gauge of least cunt 0 01mm is used to measure the diameter of a wire, the - Physics - Measurements and Experimentation

Question

12 )   W h e n   a   s c r e w   g a u g e
  o f   l e a s t   c u n t   0 01 m m   i
s   u s e d   t o   m e a s u r e   t h e
  d i a m e t e r   o f   a   w i r e ,  
t h e   r e a d i n g   o n   t h e   s l e e v
e s   i s   f o u n d   t o   b e   1 m m
  a n d   t h e   r e a d i n g   o n   t
h e   t h i m b l e   i s   f o u n d   t o
  b e   27   d i v i s i o n s ( i )   W h a t
  i s   t h e   d i a m e t e r   o f   t
h e   w i r e   i n   c m ? ( i i )   I f
  t h e   z e r o   e r r o r   i s   + 0
005   c m   w h a t   i s   t h e   c o r
r e c t   d i a m e t e r ?

Decoder_2 · Accepted Answer

Dear
student,

Main scale reading=1mm=1/10cm=0 1cm

Circular scale reading=27div

Least count=0 01mm=0 001cm

We know,

(i) Observed diameter=main scale reading+circular scale
reading×least count

Observed diameter=0 1+(27×0 001)=0 127cm

(ii) Correct diameter=observed diameter-zero error

Correct diameter=0 127-(+0 005)=0 122cm
Regards