B What will be the reading of this vernier calliper?

[Micheal_Leo]

 

[Baluncore]

That is not a vernier caliper, it is a dial caliper.
If you zeroed the dial before the reading, it reads 6.34 mm.
It is very close to 1/4" = 6.35 mm.

Each mark on the bar is one millimetre. The reading is just over six.
The dial turns once every two millimetres.
The even millimetre zero is at the top of the dial.
The odd millimetre zero is at the bottom of the dial.

 

[Micheal_Leo]

That is not a vernier caliper, it is a dial caliper.
If you zeroed the dial before the reading, it reads 6.34 mm.
It is very close to 1/4" = 6.35 mm.

Each mark on the bar is one millimetre. The reading is just over six.
The dial turns once every two millimetres.
The even millimetre zero is at the top of the dial.
The odd millimetre zero is at the bottom of the dial.

so 6 on main scale and 0.34 on dial . on main scale i am seeing cm scale

 

[Baluncore]

on main scale i am seeing cm scale

That appears to be subdivided into 1 mm divisions.
The 5 mm mark is slightly longer, as will be the 10 mm marks.
If the 10 mm multiples are marked 0, 1, 2, 3, 4 ... then it is in centimetres.
If the marks are 0, 10, 20, 30, 40 ... then it is in millimetres.

 

[Micheal_Leo]

That appears to be subdivided into 1 mm divisions.
The 5 mm mark is slightly longer, as will be the 10 mm marks.
If the 10 mm multiples are marked 0, 1, 2, 3, 4 ... then it is in centimetres.
If the marks are 0, 10, 20, 30, 40 ... then it is in millimetres.

got it thank you so 6.34cm

 

[Lnewqban]

got it thank you so 6.34cm

That measured distance is less that 1 cm (10 mm), so it can’t be that value.

 

[berkeman]

@Micheal_Leo -- One tip for improving the focus of your cell phone pictures is to tap the screen of your phone at the location of the image that you want to be in focus. Do that tap just before you take the picture, to indicate to the phone and camera what part of the image you want it to focus on.

 

[apostolosdt]

got it thank you so 6.34cm

No, it's 6.34mm. No instrument, however accurate, is useful without the user's common wisdom, sorry to be so blunt.

 

[sophiecentaur]

No, it's 6.34mm. No instrument, however accurate, is useful without the user's common wisdom, sorry to be so blunt.

It should be second nature to check the likelyhood of ones first reading. A factor of ten in measurement error should scream at the user. Using a twist drill of known size is an easy way - anyone with a calliper is sure to also have some twist drills; you don't need anything as posh as a feeler gauge.
Playing with measuring tools is a good habit to acquire; constant re-assurance about the sizes of things is bread and butter for a machinist (of any skill level).

My ex wife (a teacher) recounted the announcement at a sports day that the "Boys' 100mm race is about to start". ~We all knock PE teachers but . . .