Units and Measurements

There are 100 divisions on the circular scale of a screw gauge of pitch 1 mm. With no measuring quantity in between the jaws, the zero of the circular scale lies 5 divisions below the reference line. The diameter of a wire is then measured using this screw gauge. It is found that 4 linear scale divisions are clearly visible while 60 divisions on circular scale coincide with the reference line. The diameter of the wire is :

1. 4.65 mm
2. 4.60 mm
3. 4.55 mm
4. 3.35 mm

Least count of a vernier caliper is 120 N cm. The value of one division on the main scale is 1 mm. Then the number of divisions of main scale that coincide with N divisions of vernier scale is :

1. ( 2N - 12N )
2. ( 2N - 120N )
3. (2N - 1)
4. ( 2N - 12 )

To find the spring constant (k) of a spring experimentally, a student commits 2\% positive error in the measurement of time and 1\% negative error in measurement of mass. The percentage error in determining value of k is :

1. 5\%
2. 3\%
3. 1\%
4. 4\%

While measuring diameter of wire using screw gauge the following readings were noted. Main scale reading is 1 mm and circular scale reading is equal to 42 divisions. Pitch of screw gauge is 1 mm and it has 100 divisions on circular scale. The diameter of the wire is x50 mm. The value of x is :

1. 42
2. 71
3. 21
4. 142

Given below are two statements: In the light of the above statements, choose the most appropriate answer from the options given below.

1. Statement (I) is incorrect but statement (II) is correct
2. Both statement (I) and statement (II) are incorrect
3. Both statement (I) and statement (II) are correct
4. Statement (I) is correct but statement (II) is incorrect

In a vernier calliper, when both jaws touch each other, zero of the vernier scale shifts towards left and its 4th division coincides exactly with a certain division on main scale. If 50 vernier scale divisions equal to 49 main scale divisions and zero error in the instrument is 0.04 mm then how many main scale divisions are there in 1 cm ?

1. 5
2. 40
3. 10
4. 20

If G be the gravitational constant and u be the energy density then which of the following quantity have the dimensions as that of the uG :

1. Gravitational potential
2. pressure gradient per unit mass
3. Energy per unit mass
4. Force per unit mass

Time periods of oscillation of the same simple pendulum measured using four different measuring clocks were recorded as 4.62 s, 4.632 s, 4.6 s and 4.64 s. The arithmetic mean of these readings in correct significant figure is :

1. 5 s
2. 4.6 s
3. 4.62 s
4. 4.623 s

What is the dimensional formula of ab-1 in the equation (P + aV2 )(V - b) = RT, where letters have their usual meaning.

1. [M6 L7 T4]
2. [ M-1 L5 T3]
3. [ M0 L3 T-2]
4. [ M L2 T-2]

A vernier callipers has 20 divisions on the vernier scale, which coincides with 19th division on the main scale. The least count of the instrument is 0.1 mm. One main scale division is equal to mm.

1. 5
2. 2
3. 1
4. 0.5