Measurement of Length

Question 1

Least Count

Answer 1

The least count of an instruments is the smallest measurement that can be taken accurately with it.

Question 2

Vernier Constant

Answer 2

It is equal to the least count of the vernier which is value of 1 Main scale division - Value of one vernier scale division.

Question 3

Vernier Callipers

Answer 3

Vernier Callipers are instruments used to measure length correct up to 0.1 mm

Question 4

Zero Error ( Vernier Calliper)

Answer 4

Zero error is the length between the zero mark of the vernier callipers and the zero mark on the main scale.

Question 5

Positive Zero Error (Vernier)

Answer 5

It is a zero error in which the mark of the vernier is right to the zero mark of the main scale

Question 6

Positive Zero Error (Vernier)

Answer 6

It is a zero error in which the mark of the vernier is right to the zero mark of the main scale.

Question 7

Negative Zero Error

Answer 7

A negative zero error is a zero error in which the zero mark of the vernier scale is to the left of the main scale.

Question 8

Pitch of a screw

Answer 8

It is the linear distance moved by a screw along its axis in one complete rotation of its circular scale.

It is also the distance between two consecutive threads of a screw.

Question 9

The least count of a screw

Answer 9

The least count of a screw is the distance moved along its axis by it in rotating the circular scale by one division.

Question 10

Zero error in a Screw Gauge

Answer 10

When the studs are in contact and the zero mark of the circular scale is below/above the baseline of the main scale, there is a zero error.

Question 11

Negative Zero error (Screw gauge)

Answer 11

When the studs are in contact and the zero mark of the circular scale above the base line of main scale

Question 12

Positive Zero error (Screw gauge)

Answer 12

When the studs are in contact and the zero mark of the circular scale below the base line of main scale

Question 13

Function of outside jaws of a vernier calliper.

Answer 13

Measure the length of a rod, outer diameter of a sphere, external diameter of a hollow cylinder, etc.

Question 14

Function of inside jaws of a vernier calliper.

Answer 14

Measure internal diameter

Question 15

Function of strip of a vernier calliper.

Answer 15

Measure depth of a beaker/bottle

Question 16

Function of main scale of a vernier calliper.

Answer 16

Measure length upto 1 mm

Question 17

Function of Vernier scale of a vernier calliper.

Answer 17

Measure length upto 0.1 mm

Question 18

Function of Ratchet of a screw gauge.

Answer 18

To turn (advance) the screw

Question 19

Function of sleeve of a screw gauge.

Answer 19

Mark main scale and base line

Question 20

Function of thimble of a screw gauge.

Answer 20

To mark circular scale

Question 21

Function of Main scale of a screw gauge.

Answer 21

To read correct upto to 1 mm

Question 22

Function of Circular scale of a screw gauge.

Answer 22

To read correct upto 0.01mm

Question 23

How can we decease the least count of a screw gauge

Answer 23

(i) Increase the no. of divisions on circular scale
OR
(ii) Decrease the pitch