A Screw Guage gives the following readings when used to measure the diameter of a wire. Main scale reading = 0.0 mm Circular scale reading = 52 divisions Given that: 1 mm on the main scale corresponds to 100 divisions of the circular scale. The diameter of the wire from the above data is: 1. 0.026 cm 2. 0.005 cm 3. 0.52 cm 4. 0.052 cm

  From NCERT NEET - 2021

A Screw Guage gives the following readings when used to measure the diameter of a wire.

Main scale reading = 0.0 mm
Circular scale reading = 52 divisions
Given that: 1 mm on the main scale corresponds to 100 divisions of the circular scale.
The diameter of the wire from the above data is:

1.  0.026 cm

2.  0.005 cm

3.  0.52 cm

4.  0.052 cm

Answer: 4.  0.052 cm

Related Question:

Which of the following is the most precise device for measuring length?

A

A vernier callipers with 20 divisions on the sliding scale.

B

A screw gauge of pitch 1 mm and 100 divisions on the circular scale.

C

An optical instrument that can measure length to within a wavelength of light.

D

All instruments have same precision.

Medium

Solution:

C

An optical instrument that can measure length to within a wavelength of light.

Most precise device is the one with the minimum least count
1. Vernier Calliper
20 divisions on the sliding scale
$L.C=\frac{1}{20}mm=0.05mm$
2. Screw Gauge
pitch 1 mm and 100 divisions on the circular scale
$L.C=\frac{1mm}{100}=0.01mm$
3.optical instrument
within a wavelength of light
Wavelenght of light $\approx$ $589nm$

Question:

If the pitch of the screw is 1 mm and there are 200 divisions on the circular scale, the least count of the screw gauge will be
(A) 0.01 mm
(B) 0.02 mm
(C) 0.002 mm
(D) 0.005 mm

Solution: