The speed of light in vacuum is taken as unity. If light takes 6 ~min 40 ~s$6 \mathrm{~min} \ 40 \mathrm{~s}$ to reach the Earth from the Sun, the distance between the Sun and the Earth in new unit is:

Related Formula

Core Logic

Given: 1 MSD = 1 ~mm$1 \text{ MSD} = 1 \mathrm{~mm}$ 20 VSD = 16 MSD$20 \text{ VSD} = 16 \text{ MSD}$

Find the value of 1 VSD$1 \text{ VSD}$:

Step 1: Compute Least Count

Substitute the value of 1 MSD$1 \text{ MSD}$:

Step 2: Convert Units

Convert millimeters to centimeters to match the options:

Pattern Recognition

L.C. is strictly the difference between 1 Main Scale Division and 1 Vernier Scale Division. Always be careful about final units (cm vs mm).

Chapter Mix

Class 11 Physics: Units and Measurements

Related Formula

Core Logic

Given: Mass = 5.580 ~kg$5.580 \mathrm{~kg}$ (4 significant figures) Side length = 9.0 ~cm$9.0 \mathrm{~cm}$ (2 significant figures) Volume = (9.0 ~cm)³ = 729 ~cm³$(9.0 \mathrm{~cm})^3 = 729 \mathrm{~cm}^3$

Step 1: Apply Significant Figures

In multiplication/division, the final answer must be restricted to the lowest number of significant figures in the original data. The side length has 2 significant figures. Thus, we round 7.654...$7.654...$ to 2 significant figures. 7.654 arrow 7.7$7.654 \rightarrow 7.7$ (rounding the 6$6$ up since the next digit is 5$5$). Density ≈ 7.7 × 10³ ~kg/m³$\approx 7.7 \times 10^3 \mathrm{~kg/m}^3$. Comparing with X × 10³$X \times 10^3$, X = 7.7$X = 7.7$.

Pattern Recognition

Do not compute the exact value unthinkingly. Stop immediately when you see "keeping significant figures in view" and match the sig-figs of the least precise input (9.0 ~cm$9.0 \mathrm{~cm}$ -> 2 sig figs).

Chapter Mix

Class 11 Physics: Units and Measurements