Units and Measurement

Get insights from 125 questions on Units and Measurement, answered by students, alumni, and experts. You may also ask and answer any question you like about Units and Measurement

125
Questions
0
Discussions
0
Active Users
2
Followers

Have a question about Units and Measurement? Ask our experts

Ask Your Question

Keep it short & simple. Type complete word. Avoid abusive language.

New answer posted•a year ago

Units and Measurement Class 11th

A screw gauge of pitch 0.5mm is used to measure the diameter of uniform wire of length 6.8cm, the main scale reading is 1.5mm and circular scale reading is 7. The calculated curved surface area wire to appropriate significant figures is:

[Screw gauge has 50 divisions on its circular scale]

12 Views|Posted a year ago

Asked by Payal Gupta

Answered by

Payal Gupta | Contributor-Level 10

a year ago

Least count = $\frac{0.5}{50} m m$ = 0.01 mm

Diameter, d = 1.5 + 7 × 0.01

= 1.57

$∴$ Surface Area = (2r) $l$

= 3.4 cm²

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

The quantities which have the same dimensions as those of solid angle are:

8 Views|Posted a year ago

Asked by Alok Kumar Singh

Answered by

Alok Kumar Singh | Contributor-Level 10

a year ago

Solid angle $d Ω = \frac{d A}{r^{2}}$ has dimensions $[M^{0} L^{0} T^{0}]$

Strain $= \frac{Δ l}{l}$ has dimensions $[M^{0} L^{0} T^{0}]$

Angle measured in radians is also dimensionless $[M^{0} L^{0} T^{0}]$

$θ = \frac{l}{r}$

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

Three students S₁, S₂ and S₂ perform an experiment for determining the acceleration due to gravity (g) using a simple pendulum. They use different lengths of pendulum and record time for different number of oscillations. The observations are as shown in the table.

Student

No.

Length of Pendulum (cm)

No. of oscillations (n)

Total for n oscillations

Time period (s)

1

64.0

8

128.0

16.0

2

64.0

4

64.0

16.0

3

20.0

4

36.0

9.0

Least count of length = 0.1 cm

least count for time = 0.1 s)

If E₁, E₂ and E₃ are the percentage errors ‘g’ for students 1, 2 and 3 respectively, then the minimum percentage error is obtained by student no.___________.

14 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

$T = 2 π \sqrt[]{\frac{l}{g}}$

$g = 4 π^{2} \frac{l}{T^{2}}$

$\Rightarrow \frac{Δ g}{g} = \frac{Δ l}{l} + \frac{2 Δ T}{T}$

Student 1 will get least error because it has more number of oscillation

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

What are vernier calipers?

4 Views|Posted a year ago

Asked by Syed Aquib Ur Rahman

Answered by

Syed Aquib Ur Rahman | Contributor-Level 10

a year ago

Vernier calipers are instruments for making accurate linear measurements. They are commonly used to measure the diameter of a sphere or the depth of a hole. Its precision comes from a sliding Vernier scale that runs along a fixed main scale.

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

What types of errors in measurement are there?

5 Views|Posted a year ago

Asked by Syed Aquib Ur Rahman

Answered by

Syed Aquib Ur Rahman | Contributor-Level 10

a year ago

There are two types of errors in measurements. One is a systematic error, which comes from a fault in the measuring device. The other is a random error in measurement, which is caused by a sudden change in the environment.

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

If time (t), velocity $(υ)$ , and angular momentum $(l)$  are taken as the fundamental units. Then the dimension of mass (m) in terms of t, $υ, a n d l$  is:

4 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

Let Mass α $[t^{a} υ^{b} l^{c}] \Rightarrow [M^{1} L^{0} T^{0}] \equiv T^{a} \times {[L T^{- 1}]}^{b} \times {[M L^{2} T^{- 1}]}^{c}$

=> a – b – c = 0 c = 1, and b + 2c = 0 Þ b = -2c = -2

=> a = b + c = 1 – 2 = -1

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

The diameter of a spherical bob is measured using a vernier calipers. 9 divisions of the main scale, in the vernier caliper, are equal to 10 divisions of vernier scale. One main scale division is 1mm. The main scale reading is 10mm and 8^th division of vernier scale was found to coincide exactly with one of the main scale division. If the given vernier calipers has positive zero error of 0.04cm, then the radius of the bob is______ × 10^-2cm.

3 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

From question :

9MSD = 10VSD

LC = 1MSD – 1VSD = 1MSD - $\frac{9}{10} M S D = 0.1 M S D = 0.1 * 1 m m = 0.1 m m$

Reading = 10mm + 8 * 0.1 mm = 10.8 mm

Final reading = 10.8 mm – 0.04 mm = 10.4 mm = 104 * 10^-2 cm

So radius = 52 * 10^-2 cm

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

If velocity [V], time [T] and force [F] are chosen as the base quantities, the dimensions of the mass will be:

2 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

Using F = MA = $m \frac{V}{T}$

=> m = FTV^-1

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

Match List-I with List-II.

                  List-I                                             List-II

           (A) Torque                          (i) MLT^-1

           (B) Impulse                         (ii) MT^-2

           (C) Tension                         (iii) ML²T^-2

           (D) Surface Tension           (iv) MLT^-2

           Choose the most appropriate answer from the option given below:

7 Views|Posted a year ago

Asked by Raj Pandey

Answered by

Raj Pandey | Contributor-Level 9

a year ago

(a) Torque ® ML²T^-2 ↑ (iii)

(b) Impulse ® MlT^-1 ↑ (i)

(d) Surface Tension ↑ $\frac{M L T^{- 2}}{L} = M T^{- 2}$ (ii)

Upvote

New answer posted•a year ago

Units and Measurement Class 11th

Which of the following equations is dimensionally incorrect?

Where t = time, h = height, s = surface tension, q = angle, p = density, a, r = radius, g = acceleration due to gravity, v = volume, p = pressure, W = work done, $Γ$  = torque,  = permittivity, $\in$ = electric field, J = current density, L = length.

5 Views|Posted a year ago

Asked by Raj Pandey

Answered by

Raj Pandey | Contributor-Level 9

a year ago

$\to [W] = [τ θ] = [M L^{2} T^{- 2}] \to c o r r e c t$

$\to [h] = [L] = [\frac{2 s c o s θ}{ρ r g}] \to c o r r e c t$

$[v] = [L^{3}] [\frac{π p a^{4}}{8 η L}] = [L^{3} T^{- 1}] \to$ Incorrect

$\to J = ε \frac{\partial E}{\partial t} \to$ correct

$[A \overset{↓}{L}^{- 2}] [A \overset{↓}{L}^{- 2}]$

Upvote

Student No.	Length of Pendulum (cm)	No. of oscillations (n)	Total for n oscillations	Time period (s)
1	64.0	8	128.0	16.0
2	64.0	4	64.0	16.0
3	20.0	4	36.0	9.0

Units and Measurement

Questions

Discussions

Active Users

Followers