Units and Measurements · Question 21

A screw gauge gives the following readings when used to measure the diameter of a wire Main scale reading : 0 mm Circular scale reading : 52 divisions Given that 1 mm on main scale corresponds to 100 divisions on the circular scale. The diameter of the wire from the above data is :

1. 0.052 cm
2. 0.52 cm
3. 0.026 cm
4. 0.26 cm

If force [F], acceleration [A] and time [T] are chosen as the fundamental physical quantities. Find the dimensions of energy.

1. [F] [A-1] [T]
2. [F] [A] [T]
3. [F] [A] [T2]
4. [F] [A] [T-1]

A screw gauge has least count of 0.01 mm and there are 50 divisions in its circular scale. The pitch of the screw gauge is :

1. 0.25 mm
2. 0.5 mm
3. 1.0 mm
4. 0.01 mm

Taking into account of the significant figures, what is the value of 9.99 m - 0.0099 m?

1. 9.98 m
2. 9.980 m
3. 9.9 m
4. 9.9801 m

Dimensions of stress are :

1. [ ML2T-2]
2. [ ML0T-2]
3. [ ML-1T-2]
4. [ MLT-2]

In an experiment, the percentage of error occurred in the measurement of physical quantities A, B, C and D are 1%, 2%, 3% and 4% respectively. Then the maximum percentage of error in the measurement X, where X = A2B1/2 C1/3D3, will be :

1. 16%
2. -10\%
3. 10%
4. ( 313 )\%

A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of -0.004 cm, the correct diameter of the ball is

1. 0.521 cm
2. 0.525 cm
3. 0.053 cm
4. 0.529 cm

A physical quantity of the dimensions of length that can be formed out of c, G and e24 0 is [c is velocity of light, G is the universal constant of gravitation and e is charge]

1. c2 [G e24 0 ]1/2
2. 1c2 [ e2G 4 0 ]1/2
3. 1cG e24 0
4. 1c2 [G e24 0 ]1/2

Planck's constant (h), speed of light in vacuum (c) and Newton's gravitational constant (G) are three fundamental constants. Which of the following combinations of these has the dimension of length ?

1. hGc3/2
2. hGc5/2
3. hcG
4. Gch3/2

If dimensions of critical velocity vc of a liquid flowing through a tube are expressed as [ x y rz] where , and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of x, y and z are given by

1. -1, -1, -1
2. 1, 1, 1
3. 1, -1, -1
4. -1, -1, 1