CBSE Class 10 Mathematics Basic 2023: question 19
Set in the CBSE Class 10 board exam of 2023, paper 430/4/1, section A, question 19, for 1 mark. Try it first; the hints and our step-by-step solution are below.
Q19 · 1 mark · Assertion-reasonCompetency-basedCircles
Assertion (A): A tangent to a circle is perpendicular to the radius through the point of contact.
Reason (R): The lengths of tangents drawn from an external point to a circle are equal.
- (A)Both Assertion (A) and Reason (R) are true and Reason (R) gives the correct explanation of Assertion (A).
- (B)Both Assertion (A) and Reason (R) are true but Reason (R) does not give the correct explanation of Assertion (A).
- (C)Assertion (A) is true but Reason (R) is false.
- (D)Assertion (A) is false but Reason (R) is true.
Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 430/4/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
Check each statement separately against the theorems you know.
Hint 2
Does the equality of tangent lengths prove the perpendicularity property?
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.
Both statements are standard theorems, so both A and R are true.
- 1 mark
R (equal tangent lengths) does not explain why the tangent is perpendicular to the radius. Answer: option (B).
Answer: Option (B)
Where the marks are
- Identifies both as true and R not explaining A (1 mark)
Revise the chapter
- Chapter: Circles (notes, formulas, where marks are lost and every past question)
- Topic: Tangent Perpendicular to Radius Theorem
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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.