Units and Measurements — Class 11 Physics NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 11 Physics chapter "Units and Measurements" — 8 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 11 Physics chapter "Units and Measurements" — 8 important questions with detailed answers for CBSE board e…
By Syllab.in · Updated
Key Questions Covered:
- Define the SI unit of length and explain how the metre is defined.
- A student measures the thickness of a single sheet of paper using a screw gau…
- Express the following in scientific notation with appropriate significant fig…
- + 5 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| Define the SI unit of length and explain how the metre is… | ✓ Solved |
| A student measures the thickness of a single sheet of pap… | ✓ Solved |
| Express the following in scientific notation with appropr… | ✓ Solved |
Showing 3 of 8 questions
Q1: Define the SI unit of length and explain how the metre is defined.
The SI unit of length is the metre (m).
Definition: The metre is defined as the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second.
This definition was adopted at the 17th General Conference on Weights and Measures (CGPM) in 1983. It is based on the...
Q2: A student measures the thickness of a single sheet of paper using a screw gauge. If the main scale reading is 0 mm and the circular scale reading is 45 divisions (least count = 0.01 mm), calculate the thickness of the paper.
Given:
Main scale reading (MSR) = 0 mm
Circular scale reading (CSR) = 45 divisions
Least count (LC) = 0.01 mm
Formula:
Reading = MSR + (CSR × LC)
Step 1: Identify the main scale reading
MSR = 0 mm
Step 2: Calculate the circular scale contribution
CSR contribution = 45 × 0.01 mm = 0.45 mm
Step 3:...
Q3: Express the following in scientific notation with appropriate significant figures: (a) 0.000456 kg (b) 45000 m (c) 0.0050 A
Step 1: Identify significant figures and convert to scientific notation
(a) 0.000456 kg
- Significant figures: 3 (the zeros before 4 are not significant)
- Scientific notation: 4.56 × 10⁻⁴ kg
(b) 45000 m
- Significant figures: 2 (assuming only 4 and 5 are significant; trailing zeros without decima...
Showing 3 of 8 questions. Visit the full page for complete solutions.