﻿ A screw gauge with a pitch of 0.5 mm and a circular scale with 50 divisions is used to measure the thickness of a thin sheet of Aluminium. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact, the 45th division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness of the sheet if the main scale reading is 0.5 mm and the 25th division coincides with the main scale line? | Units and Measurement

## Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

## Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

## Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

# 1.A screw gauge with a pitch of 0.5 mm and a circular scale with 50 divisions is used to measure the thickness of a thin sheet of Aluminium. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact, the 45th division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness of the sheet if the main scale reading is 0.5 mm and the 25th division coincides with the main scale line? 0.75 mm 0.80 mm 0.70 mm 0.70 mm

A.

0.75 mm

Given that the screw gauge has zero error.
So, least count of screw gauge = 0.5/50 mm

The thickness of the sheet if the main scale reading is 0.5 mm and the 25th division coincides with the main scale line. we have

=0 .50 mm + (25) x 0.5/50 mm
= 0.50 mm + 0.25 mm = 0.75 mm

971 Views

2.

A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it?

• A meter scale.

• A vernier calliper where the 10 divisions in vernier scale match with 9 division in the main scale and main scale have 10 divisions in 1 cm.

• A screw gauge having 100 divisions in the circular scale and pitch as 1 mm.

• A screw gauge having 100 divisions in the circular scale and pitch as 1 mm.

450 Views

3.

Let [ε0] denote the dimensional formula of the permittivity of vacuum. If M = mass, L = length, T = time and A = electric current, then

• 0] = [M-1L-3T2A]

• 0] = [M-1L-3T4A2]

• 0] =[M-2L2T-1A-2]

• 0] =[M-2L2T-1A-2]

448 Views

4.

A spectrometer gives the following reading when used to measure the angle of a prism.
Given that 1 division on the main scale corresponds to 0.5 degree. Total divisions on the vernier scale is 30 and match with 29 divisions of the main scale. The angle of the prism from the above data

• 58.59 degree

• 58.77 degree

• 58.65 degree

• 58.65 degree

1035 Views

5.

A screw gauge gives the following reading when used to measure the diameter of a wire. Main scale reading : 0 mm
Given that 1 mm on the main scale corresponds to 100 divisions of the circular scale. The diameter of wire from the above data is

• 0.052 cm

• 0.026 cm

• 0.005

• 0.005

882 Views

6.

The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1 × 10–3 are

• 5,1,2

• 5,1,5

• 5,5,2

• 5,5,2

228 Views

7.

In an experiment, the angles are required to be measured using an instrument. 29 divisions of the main scale exactly coincide with the 30 divisions of the vernier scale. If the smallest division of the main scale is half–a–degree (= 0.5o° ), then the least count of the instrument is

• one minute

• half minute

• One degree

• One degree

295 Views

8.

The dimension of magnetic field in M, L, T and C (Coulomb) is given as

• MLT−1C−1

• MT2C−2

• MT−1C−1

• MT−1C−1

176 Views

9.

Two full turns of the circular scale of a screw gauge cover a distance of 1 mm on its main scale. The total number of divisions on the circular scale is 50. Further, it is found that the screw gauge has a zero error of − 0.03 mm while measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale divisions in line with the main scale as 35. The diameter of the wire is

• 3.32 mm

• 3.73 mm

• 3.67 mm

• 3.67 mm

207 Views

10.

Two full turns of the circular scale of a screw gauge cover a distance of 1 mm on its main scale. The total number of divisions on the circular scale is 50. Further, it is found that the screw gauge has a zero error of − 0.03 mm while measuring the diameter of a thin wire, a student notes the main scale reading of 3 mm and the number of circular scale divisions in line with the main scale as 35. The diameter of the wire is

• 3.32 mm

• 3.73 mm

• 3.67 mm

• 3.67 mm

245 Views