Units Measurements Exemplar — Class 11 Physics NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 11 Physics chapter "Units Measurements Exemplar" — 5 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 11 Physics chapter "Units Measurements Exemplar" — 5 important questions with detailed answers for CBSE bo…
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NCERT Solutions for Class 11 Physics — Units Measurements Exemplar. Step-by-step answers to all 5 textbook questions from this chapter, written for CBSE board preparation and free to use.
Units Measurements Exemplar — All 5 Questions Solved
Q1. Express 5000 g in kg and mg.
5000 g = 5000/1000 kg = 5 kg. 5000 g = 5000 × 1000 mg = 5 × 10^6 mg.
Q2. Convert 72 km/h to m/s.
72 km/h = 72 × (1000 m)/(3600 s) = 72 × 5/18 = 20 m/s.
Q3. Find dimensions of velocity.
Velocity = displacement/time. Dimension = [L]/[T] = [LT^-1].
Q4. Check dimensionally if equation v = u + at is correct.
LHS: v has dimension [LT^-1]. RHS: u is [LT^-1], at = [LT^-2][T] = [LT^-1]. LHS = RHS dimensionally. Equation is dimensionally correct.
Q5. What is significant figures? Round 23.456 to 3 significant figures.
Significant figures are all digits that carry meaningful information about precision. 23.456 rounded to 3 SF = 23.5 (keeping 2, 3, 5 and rounding up last digit 4 to 5).
How to Use These Solutions
Attempt each question yourself first and only then compare with the worked answer. Marks in the CBSE board exam are awarded for the METHOD as much as the final result, so reproduce the steps rather than memorising the last line. Where a solution states a law, a formula or a definition, learn that wording — examiners look for it.
Related practice for this chapter: chapter MCQs, previous-year questions, revision notes and sample papers.