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# Units and Measurement

11th Class - CBSE - Physics - 2754 Questions - 0 Concepts

#### Important Questions

Q1 Subjective Hard
The edge of a cube is measured using a vernier callipers. [9 divisions of the main scale is equal to 10 divisions of vernier scale and 1 main scale division is 1 mm]. The main scale division reading is 10 and 1 division of vernier scale was found to be coinciding with the main scale. The mass of the cube is 2.736 gm. Calculate the density in $\mathrm{g}\mathrm{m}/\mathrm{c}\mathrm{m}^{3}$ up to correct significant figures.

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1 Verified Answer | Published on 18th 08, 2020

Q2 Single Correct Hard
From the following combinations of physical constants (expressed through their usual symbols) the only combination, that would have the same value in different system of units, is:
• A. $\dfrac {ch}{2\pi \epsilon_{0}^{2}}$
• B. $\dfrac {e^2}{2\pi \epsilon_0Gm_{e}^{2}}(m_e=$ mass of electron)
• C. $\dfrac {\mu_0 \epsilon_0}{c^2}\dfrac {G}{he^2}$
• D. $\dfrac {2\pi \sqrt {\mu_0\epsilon_0}}{ce^2}\dfrac {h}{G}$

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q3 Subjective Hard
To find the value of g using simple pendulum, $T = 2.00 s$ and $l = 1.00 m$ were measured. Estimate maximum permissible error in g. Also find the value of g.

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q4 Single Correct Hard
If the velocity of light $C$, the universal gravitational constant $G$, and Planck's constant $h$ are chosen as fundamental units, the dimension of mass in this system are
• A. $h^{1/2}C^{1/2}G^{-1/2}$
• B. $h^{-1}C^{-1}G$
• C. $hCG^{-1}$
• D. $hCG$

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q5 Subjective Hard
If  velocity (V), force (F) and time (T) are chosen as fundamental quantities, express (a) mass and (b) energy in terms of V, F and T.

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q6 Multiple Correct Hard
Which of the following pairs have the same dimensions?
(L = inductance, C = capacitance, R = Resistance)
• A. $\dfrac{L}{R}$ and CR
• B. LR and CR
• C. $\dfrac{L}{R}$ and $\sqrt{LC}$
• D. RC and $\dfrac{1}{LC}$

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q7 Single Correct Hard
Two plates have lengths measured as $(1.9 \pm 0.3)m$ and $(3.5 \pm0.2)m$. Calculate their combined length with error limits.
• A. $(5.4 \pm 0.5)m$
• B. $(5.4 \pm 2.5)m$
• C. $(4.4 \pm 0.5)m$
• D. $(5.4 \pm 1.5)m$

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q8 Subjective Hard
In Searle's experiment to find Young's modulus, the diameter of wire is measured as $D = 0.05cm$, the length of wire is $L = 125 cm,$ and when a weight, $m = 20 kg$ is the put, extension in wire was found to be $0.100 cm$. Find the maximum permissible error in Young's modulus (Y).

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q9 Single Correct Hard
With due regard to significant figures, add the following:
a. 953 and 0.324
b. 953 and 0.625
c. 953.0 and 0.324
d. 953.0 and 0.374
• A. a. $953$; b. $954$ c. $953.3$ d. $953.4$
• B. a. $953$; b. $955$ c. $953.3$ d. $953.4$
• C. a. $952$; b. $954$ c. $953.3$ d. $953.4$
• D. a. $953$; b. $954$ c. $953.3$ d. $952.4$

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Q10 Subjective Hard
In an experiment, the following observations were recorded:
$L = 2.820 m, M = 3.00 kg, l = 0.087 cm$, diameter $D = 0.041 cm$. Taking $g = 9.81 m s^{-2}$ and using the formula, Y =$\frac{4Mg}{\pi D^2 l}$, find the maximum permissible error in Y.

Asked in: Physics - Units and Measurement

1 Verified Answer | Published on 18th 08, 2020

Questions 244531
Subjects 8
Chapters 125
Enrolled Students 217