NEET 2022 Physics Significant Figures MCQ Question

Chapter: Units and Measurements

Class: 11 Physics Topic: Significant Figures Difficulty: 🟢 Easy

✅ Ans: B — $14\times10^2\ m^2$

Area:

$$A=l\times b$$ $$A=55.3\times25=1382.5\ m^2$$

For multiplication, the result should have the same number of significant figures as the measurement having the least significant figures.

• $55.3$ → 3 significant figures
• $25$ → 2 significant figures

Therefore, answer must have 2 significant figures:

$$1382.5\rightarrow 1.4\times10^3$$

or

$$\boxed{14\times10^2\ m^2}$$

❌ Why other options are wrong?

• 1382.5 ❌ Too many significant figures.
• $14\times10^2$ ✅ 2 significant figures.
• $138\times10^1$ ❌ Has 3 significant figures.
• 1382 ❌ Has 4 significant figures.

📌 NCERT Rule

For multiplication/division:

$$\boxed{\text{Result has the same number of significant figures as the least precise measurement.}}$$

🧠 NEET Trick

Multiply → count significant figures → keep the least.

$$55.3(3\,SF)\times25(2\,SF) \Rightarrow \boxed{14\times10^2}$$

Final Answer: $\boxed{B}$