CBSE Class 10 Mathematics Standard 2024: question 13
Set in the CBSE Class 10 board exam of 2024, paper 30/1/1, section A, question 13, for 1 mark. Try it first; the hints and our step-by-step solution are below.
Q13 · 1 mark · MCQSurface Areas and Volumes
A solid sphere is cut into two hemispheres. The ratio of the surface areas of sphere to that of two hemispheres taken together, is:
- (A)1 : 1
- (B)1 : 4
- (C)2 : 3
- (D)3 : 2
Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 30/1/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
Cutting creates two new flat circular faces.
Hint 2
TSA of a hemisphere .
Step-by-step solution
Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.
Surface area of the sphere . Each hemisphere has total surface area , so the two together have .
- 1 mark
Ratio . The answer is option (C).
Answer: 2 : 3, option (C)
Where the marks are
- Uses TSA of a hemisphere to get the ratio , option (C) (1 mark)
Revise the chapter
- Chapter: Surface Areas and Volumes (notes, formulas, where marks are lost and every past question)
- Topic: Surface Area and Volume Formulae Revision
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The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.