Question 72:
One Angstrom (Å) is equal to:
One Angstrom equals 0.1 nanometer. The correct answer is (A) 0.1 nanometer.
Option Analysis
Option (A) 0.1 nanometer
1 Å = 10⁻¹⁰ m and 1 nm = 10⁻⁹ m, so 1 Å = 0.1 nm (or 10 Å = 1 nm). This standard conversion is used in molecular biology for DNA helix measurements.
Option (B) 0.01 nanometer
This equals 0.1 pm (picometers), too small—1 Å is ten times larger than 0.01 nm.
Option (C) 0.001 nanometer
This represents 0.01 pm or 10 fm (femtometers), equivalent to atomic nuclei scales, not molecular dimensions.
Option (D) 0.01 micrometer
1 μm = 10⁻⁶ m, so 0.01 μm = 10 nm (100 Å), 100 times larger than 1 Å.
One angstrom equals 0.1 nanometer, essential for GATE Life Sciences questions on biomolecular dimensions like DNA base spacing (3.4 nm per turn).
Unit Breakdown
| Unit | Size (meters) | Biology Use |
|---|---|---|
| 1 Å | 10⁻¹⁰ m | Atomic bonds, protein structures |
| 1 nm | 10⁻⁹ m | DNA width, viruses |
| 1 μm | 10⁻⁶ m | Cell organelles |
Quick Conversions
-
10 Å = 1 nm
-
100 Å = 10 nm = 0.01 μm
Exam Tip
Memorize “1 Å = 0.1 nm” for structural biology MCQs—avoids trick options like micrometers.
