Length, breadth and thickness of a strip having a uniform cross section are measured to be 10.5 cm, 0.05 mm, and , respectively. Which of the following option(s) give(s) the volume of the strip in with correct significant figures:
- (A)
- (B)
- (C)
- (D)✓ Correct
Answer: (D)
Solution
Given measurements:
Volume = L × b × t = 10.5 × 0.005 × 6.0 × 10⁻⁴ cm³
The result must have only 1 significant digit (limited by the measurement with the fewest significant digits).
V = 10.5 × 0.005 × 6.0 × 10⁻⁴ = 3.15 × 10⁻⁵ cm³
Rounding to 1 significant digit: V = 3 × 10⁻⁵ cm³
- L = 10.5 cm → 3 significant digits
- b = 0.05 mm = 0.005 cm → 1 significant digit
- t = 6.0 μm = 6.0 × 10⁻⁴ cm → 2 significant digits
Volume = L × b × t = 10.5 × 0.005 × 6.0 × 10⁻⁴ cm³
The result must have only 1 significant digit (limited by the measurement with the fewest significant digits).
V = 10.5 × 0.005 × 6.0 × 10⁻⁴ = 3.15 × 10⁻⁵ cm³
Rounding to 1 significant digit: V = 3 × 10⁻⁵ cm³
JEE Advanced · 2025 · 18 May 2025 · Paper 1 · One or more correct options