﻿ 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  | Units and Measurement

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# 1.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

D.

3.67 mm

Diameter = M.S.R. + C.S.R × L.C. + Z.E.
= 3 + 35 × (0.5/50) + 0.03 = 3.38 mm

207 Views

2.

Which one of the following represents the correct dimensions of the coefficient of viscosity?

• ML−1 T−2

• MLT−1

• ML−1 T−1

• ML−1 T−1

C.

ML−1 T−1 403 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]

B.

0] = [M-1L-3T4A2]

From Coulomb's Law, F On Substituting the units, we get 448 Views

4.

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

A.

one minute

1VSD = 29/30 MSD
L.C. = 1 MSD – 1 VSD
= 1/30 MSD 295 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

A.

0.052 cm

Least count of screw gauge =1/100 mm = 0.01 mn
Diameter - Divisions on cirular scale × least count + main scale reading = 52 × 1/100 + 0
100 = 0.52 mm
diameter = 0.052 cm

882 Views

6.

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.

B.

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.

If student measures 3.50 cm, it means that there is an uncertainty of order 0.01 cm
For vernier scale with 1 MSD = 1mm
and 9 MSD = 10 VSD
LC of vernier scale with 1 MSD - 1 VSD 450 Views

7.

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

D.

3.67 mm

Diameter = M.S.R. + C.S.R × L.C. + Z.E.
= 3 + 35 × (0.5/50) + 0.03
= 3.38 mm

245 Views

8.

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

C.

58.65 degree

1035 Views

9.

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

A.

5,1,2

228 Views

10.

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

C.

MT−1C−1

F = qvB
B = F/qv
= MC−1 T−1

176 Views