UPSC Prelims 2007 Q14: Science & Technology – Materials & Engineering
Consider the following statements:
1. The series of international paper sizes is based on A0 size whose area is 0.5 m² (approx).
2. The area of A4 size paper is 1⁄8th of the A0 size paper.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2
- (d) Neither 1 nor 2
Answer: (d) Neither 1 nor 2
Explanation
International (ISO 216) paper sizes
| Statement | Fact check |
|---|---|
| 1. A0 area ≈ 0.5 m² | False — A0's actual area is approximately 1 m² (841×1189mm) |
| 2. A4 area = 1/8th of A0 | False — each step halves the area, so A4 is 1/16th of A0, not 1/8th |
Both statements misstate the ISO 216 standard, so the answer is Neither 1 nor 2.
Answer: (d) Neither 1 nor 2.
Why each option is right or wrong
- (a) Incorrect. Statement 1 is false — A0 is about 1 m², not 0.5 m².
- (b) Incorrect. Statement 2 is false — A4 is 1/16th, not 1/8th, of A0.
- (c) Incorrect. Neither statement is correct.
- (d) CORRECT. Both statements misstate the ISO 216 paper-size specification.
Key point
ISO A0 ≈ 1 m², and A4 is 1/16th (not 1/8th) of A0's area — both given statements are false.
Remember
A0 paper ≈ 1 m²; A4 = 1/16th of A0's area.
Common mistakes
- Assuming A0's area is 0.5 m² rather than the correct ~1 m².
- Forgetting each step in the A-series halves the area, making A4 1/16th of A0, not 1/8th.
- Not working through the halving sequence (A0→A1→A2→A3→A4 = four halvings = 1/16).
Exam tip
A0 = ~1 m²; each successive A-size halves the area; A4 is exactly 4 halvings from A0, i.e., 1/16th.
Sources
- International Organization for Standardization — ISO 216:2007, Writing paper and certain classes of printed matter — Trimmed sizes — A and B series
- Encyclopaedia Britannica — paper size