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CBSE Class 10 Mathematics Chapter 10 Circles — 20 MCQs with Answers

Chapter 10 Circles in CBSE Class 10 Mathematics introduces elegant theorems about angles, chords, and cyclic quadrilaterals that have stood the test of time since Euclid. The 2025 board paper typically carries 4-5 marks from this chapter, often as MCQs (1 mark each) or assertion-reason questions. These 20 MCQs mirror the exact difficulty spectrum you will face—from direct recall of the angle-at-centre theorem to multi-step cyclic quadrilateral problems and HOTS questions that test your ability to combine multiple concepts. Solve them under timed conditions, check your answers immediately, and note the reasoning. This active practice builds both speed and confidence for the board exam.

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Key takeaways

  • The angle subtended by a chord at the centre is exactly twice the angle subtended at any point on the circumference on the same arc.
  • All angles in the same segment of a circle (formed by a chord) are equal, regardless of where the point lies on that arc.
  • Any angle subtended by a diameter from a point on the circumference is always 90°, making it a reliable test for right angles in circle problems.
  • In a cyclic quadrilateral, opposite angles are supplementary—they always add up to 180°—and this property uniquely defines cyclic quadrilaterals.
  • The converse is equally powerful: if opposite angles of any quadrilateral sum to 180°, the four vertices must lie on a circle, proving it is cyclic.
  • MCQs in CBSE Mathematics papers carry 1 mark each and test quick recall, formula application, and logical reasoning under time pressure.
  • Practising 15-20 MCQs daily from each chapter sharpens pattern recognition and reduces silly errors in board exams.

Angle Subtended by Chord at Centre and Circumference — MCQs

The cornerstone theorem of this chapter states that the angle a chord subtends at the centre of a circle is exactly twice the angle it subtends at any point on the major arc. This theorem appears in nearly every CBSE paper, often disguised in diagrams where you must identify the central and inscribed angles first. Mastering this concept unlocks most circle geometry problems. The four MCQs below test your ability to apply the 2:1 ratio, recognize when a diameter is involved (leading to 180° at centre), and solve reverse problems where the circumference angle is unknown. Remember: always check which arc the point lies on—major or minor—because angles on opposite arcs are supplementary.
  • **Q1.** A chord PQ of a circle with centre O subtends an angle of 60° at point R on the major arc. What is the measure of ∠POQ? (A) 30° (B) 60° (C) 120° (D) 180° **Answer: (C) 120°** — By the angle-at-centre theorem, ∠POQ = 2 × ∠PRQ = 2 × 60° = 120°.
  • **Q2.** In a circle, a chord AB subtends an angle of 80° at the centre O. The angle subtended by the same chord at a point C on the remaining part of the circle is: (A) 40° (B) 80° (C) 100° (D) 160° **Answer: (A) 40°** — Angle at circumference = half the central angle = 80° ÷ 2 = 40°.
  • **Q3.** If a chord subtends an angle of 90° at the centre of a circle, what is the angle it subtends at any point on the major arc? (A) 45° (B) 90° (C) 135° (D) 180° **Answer: (A) 45°** — Angle at circumference = 90° ÷ 2 = 45° (always half the central angle).
  • **Q4.** A chord MN of a circle subtends an angle of 50° at a point on the minor arc. The angle subtended by the same chord at the centre is: (A) 25° (B) 50° (C) 100° (D) 130° **Answer: (C) 100°** — First, angle on major arc = 180° − 50° = 130°; then central angle = 2 × 130° = 260°? No—angle on minor arc is external, so central = 2 × 50° = 100°.

Angles in the Same Segment — MCQs

When a chord divides a circle into two arcs (or segments), every angle subtended by that chord from any point on the same arc is equal. This is a direct consequence of the angle-at-centre theorem: since all points on the same arc subtend the same central angle, they all yield the same inscribed angle (half that central angle). CBSE loves to test this by drawing multiple points on one arc and asking you to identify equal angles or to prove congruence. The four MCQs below require you to spot equal angles, apply the property in cyclic figures, and distinguish between angles on the major versus minor arc. Always mark the arc first—this visual step prevents mix-ups.
  • **Q5.** Points A, B, C, D lie on a circle such that chord AC subtends ∠ABC = 65° and ∠ADC is on the same arc. The measure of ∠ADC is: (A) 32.5° (B) 65° (C) 115° (D) 130° **Answer: (B) 65°** — Angles in the same segment (same arc) are equal, so ∠ADC = ∠ABC = 65°.
  • **Q6.** In a circle, a chord PQ subtends ∠PRQ = 40° at point R and ∠PSQ at point S, both on the major arc. What is ∠PSQ? (A) 20° (B) 40° (C) 80° (D) 140° **Answer: (B) 40°** — Both R and S lie on the same arc, so ∠PSQ = ∠PRQ = 40° (angles in same segment).
  • **Q7.** If ∠BAC = 55° and ∠BDC are angles subtended by chord BC at points A and D on the same side of BC, then ∠BDC is: (A) 27.5° (B) 55° (C) 110° (D) 125° **Answer: (B) 55°** — Angles in the same segment are equal.
  • **Q8.** A chord divides a circle into two arcs. If an angle of 48° is formed at one point on the major arc, the angle at another point on the same major arc is: (A) 24° (B) 48° (C) 96° (D) 132° **Answer: (B) 48°** — Angles in the same segment remain constant at 48°.

Angle in a Semicircle and Diameter Properties — MCQs

One of the most elegant results in circle geometry: any angle subtended by a diameter from a point on the circumference is a right angle (90°). This follows from the angle-at-centre theorem—since a diameter subtends 180° at the centre, the inscribed angle is 180° ÷ 2 = 90°. CBSE frequently uses this in proof-based questions and diagram-based MCQs where you must identify the diameter first. The four MCQs below test recognition of diameters, application of the 90° property, and reverse reasoning (if an angle is 90°, the chord must be a diameter). This property is also a quick way to verify right-angled triangles inscribed in circles.
  • **Q9.** AB is a diameter of a circle with centre O. If C is any point on the circle (not A or B), then ∠ACB is: (A) 45° (B) 60° (C) 90° (D) 180° **Answer: (C) 90°** — Angle in a semicircle is always 90°.
  • **Q10.** In a circle, PQ is a diameter and R is a point on the circle. If ∠PRQ = 90°, which statement is true? (A) PR is a diameter (B) QR is a diameter (C) PQ is a diameter (D) Triangle PQR is equilateral **Answer: (C) PQ is a diameter** — Since ∠PRQ = 90°, PQ must be the diameter (angle in semicircle property).
  • **Q11.** A circle has diameter 10 cm. A point M on the circle subtends an angle with the endpoints of the diameter. This angle measures: (A) 30° (B) 45° (C) 60° (D) 90° **Answer: (D) 90°** — Any point on the circle forms a 90° angle with the diameter endpoints.
  • **Q12.** If AB is a diameter and ∠CAB = 35° where C is on the circle, then ∠ABC is: (A) 35° (B) 45° (C) 55° (D) 90° **Answer: (C) 55°** — ∠ACB = 90° (semicircle), so in △ABC: 35° + ∠ABC + 90° = 180° → ∠ABC = 55°.

Cyclic Quadrilateral Properties — MCQs

A cyclic quadrilateral has all four vertices on the circumference of a circle, and its defining property is that opposite angles are supplementary—they add to 180°. This property appears in nearly every CBSE paper, either as a direct MCQ or embedded in a diagram-based problem. The converse is equally testable: if opposite angles sum to 180°, the quadrilateral is cyclic. The four MCQs below test forward application (finding unknown angles), converse reasoning (proving a quadrilateral is cyclic), and multi-step problems involving exterior angles. Always check both pairs of opposite angles to confirm the cyclic property, and remember that the sum of all four angles in any quadrilateral is 360°—a useful cross-check.
  • **Q13.** ABCD is a cyclic quadrilateral. If ∠A = 70° and ∠C = 110°, which property is satisfied? (A) Adjacent angles are equal (B) Opposite angles are supplementary (C) All angles are equal (D) Diagonals are equal **Answer: (B) Opposite angles are supplementary** — 70° + 110° = 180°, confirming the cyclic property.
  • **Q14.** In cyclic quadrilateral PQRS, ∠P = 85°. What is ∠R? (A) 85° (B) 90° (C) 95° (D) 180° **Answer: (C) 95°** — Opposite angles sum to 180°, so ∠R = 180° − 85° = 95°.
  • **Q15.** If opposite angles of a quadrilateral are 78° and 102°, the quadrilateral is: (A) a rectangle (B) a cyclic quadrilateral (C) a rhombus (D) none of these **Answer: (B) a cyclic quadrilateral** — 78° + 102° = 180°, satisfying the converse of the cyclic quadrilateral theorem.
  • **Q16.** In cyclic quadrilateral KLMN, ∠K = 2x, ∠L = 3x, ∠M = 4x, ∠N = 3x. Find x. (A) 15° (B) 20° (C) 25° (D) 30° **Answer: (D) 30°** — Sum = 2x + 3x + 4x + 3x = 12x = 360° → x = 30°; verify: ∠K + ∠M = 60° + 120° = 180° ✓.

Application, HOTS, and Assertion-Reason MCQs

CBSE Class 10 Mathematics papers now include higher-order thinking questions that combine multiple theorems or require you to reason across steps. Assertion-reason MCQs test both your knowledge of a statement and your ability to justify it. The four MCQs below are at HOTS level: they involve combining the angle-at-centre theorem with cyclic quadrilateral properties, proving quadrilaterals are cyclic, and solving for unknowns in complex diagrams. Approach these by sketching a diagram if one is not provided, labeling all known angles, and applying theorems one step at a time. These questions separate average scorers from high achievers in board exams—practice them under timed conditions.
  • **Q17.** Assertion (A): If a quadrilateral has one pair of opposite angles summing to 180°, it is cyclic. Reason (R): All cyclic quadrilaterals have both pairs of opposite angles summing to 180°. (A) Both A and R are true, R is correct explanation (B) Both true, R is not correct explanation (C) A true, R false (D) A false, R true **Answer: (D) A false, R true** — One pair summing to 180° is insufficient; both pairs must sum to 180° to be cyclic.
  • **Q18.** A chord of a circle subtends 120° at the centre. The angle subtended at a point on the minor arc is: (A) 30° (B) 60° (C) 120° (D) 150° **Answer: (D) 150°** — Angle on major arc = 120° ÷ 2 = 60°; on minor arc = 180° − 60° = 150° (angles on opposite arcs are supplementary).
  • **Q19.** In cyclic quadrilateral ABCD, ∠A = 3∠C. Find ∠A. (A) 45° (B) 60° (C) 90° (D) 135° **Answer: (D) 135°** — Let ∠C = x, then ∠A = 3x. Since ∠A + ∠C = 180°, 3x + x = 180° → x = 45°, ∠A = 3 × 45° = 135°.
  • **Q20.** A circle passes through vertices of a triangle ABC. If ∠BAC = 50° and BC is a diameter, find ∠ABC. (A) 40° (B) 50° (C) 90° (D) 130° **Answer: (A) 40°** — Since BC is diameter, ∠BAC is inscribed in semicircle, so ∠BCA = 90°. In △ABC: 50° + ∠ABC + 90° = 180° → ∠ABC = 40°.

How to Attempt MCQs in the CBSE Paper — Strategy Section

Multiple-choice questions in the CBSE Class 10 Mathematics paper carry 1 mark each and are designed to test quick recall, formula application, and logical reasoning under strict time limits. The 2025 paper typically includes 20 MCQs across all chapters, and you have roughly 1 minute per question. Success depends on three habits: (i) read the question twice before looking at options to avoid distraction, (ii) eliminate obviously wrong answers first to improve your odds if you must guess, and (iii) always verify your answer by a quick reverse calculation or substitution—many MCQs are designed to trap students who rush. For assertion-reason questions, evaluate the assertion independently first, then check if the reason logically supports it. If you are stuck, mark the question, move on, and return with fresh eyes in the last 10 minutes. Never leave an MCQ blank—there is no negative marking, so educated guessing is better than omission. Practice 15-20 MCQs daily from each chapter in the final month before boards to build pattern recognition and reduce silly errors. Time yourself strictly: 20 MCQs in 20 minutes is the target pace.
  • **Read the question stem carefully:** Underline keywords like 'cyclic', 'diameter', 'major arc', 'minor arc' to avoid misreading the setup.
  • **Draw a quick sketch:** Even a rough circle with labeled points takes 10 seconds and prevents visualization errors in angle problems.
  • **Use elimination:** If you can rule out two options confidently, your guess between the remaining two has 50% accuracy.
  • **Verify by substitution:** After choosing an answer, plug it back into the question to see if it satisfies all conditions—this catches calculation slips.
  • **Watch for 'NOT' and 'EXCEPT':** CBSE occasionally phrases questions negatively; highlight these words so you do not pick the correct statement by mistake.
  • **Manage time ruthlessly:** Spend no more than 60 seconds per MCQ. If stuck, mark it and move on—returning later often brings clarity.
  • **Assertion-Reason protocol:** First decide if A is true, then if R is true, then if R explains A. Many students lose marks by not following this sequence.

Why CBSETUTOR.ai Is the Smart Revision Partner for Circles

Chapter 10 Circles has only a handful of core theorems, but CBSE exam questions combine them in dozens of creative ways—cyclic quadrilaterals nested inside triangles, chords that are also diameters, angles on opposite arcs. Textbook examples cover the basics, but board-level MCQs demand pattern recognition that comes only from solving 50+ varied problems. CBSETUTOR.ai gives your child exactly that: a 24×7 AI tutor trained on NCERT and past CBSE papers, accessible on any device. Your child can snap a photo of any circle geometry problem—whether from school worksheets, sample papers, or even a tricky board paper from 2023—and get a step-by-step solution in seconds, written in clear, exam-friendly language. The AI explains why the angle-at-centre theorem applies, how to spot a cyclic quadrilateral, and which property to use when. Beyond Circles, CBSETUTOR.ai covers every Class 10 chapter in Mathematics, Science, and Social Science at one flat price: ₹999 per month for Classes 6 to 12, no hidden fees, no per-question charges. Start with a 3-day free trial—no credit card required. Most Delhi NCR and Mumbai families see a jump in confidence within the first week because the child gets instant help exactly when they are stuck, not three days later when the tutor visits. Visit CBSETUTOR.ai today and turn Circles from a confusion into a scoring chapter.
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Frequently asked questions

How many marks does Chapter 10 Circles typically carry in the CBSE Class 10 board exam?+
Circles usually carries 4-6 marks in the board paper, distributed as 2-3 MCQs (1 mark each), one 2-mark short-answer question, and occasionally a 3-mark proof-based question. The 2024 and 2025 sample papers show consistent weightage for cyclic quadrilaterals and angle-at-centre theorem.
What is the most important theorem in Chapter 10 Circles for MCQs?+
The angle-at-centre theorem—that the angle subtended by a chord at the centre is twice the angle at the circumference—is the foundation. Over 60% of Circles MCQs in past CBSE papers directly or indirectly test this theorem, so master it first.
How do I quickly identify a cyclic quadrilateral in a diagram?+
Look for a quadrilateral inscribed in a circle with all four vertices on the circumference. If the diagram does not show a circle, check if opposite angles sum to 180°—that is the test for a cyclic quadrilateral by the converse theorem.
Are assertion-reason questions on Circles difficult in the board exam?+
Assertion-reason MCQs test both factual knowledge and logical reasoning. In Circles, common assertions involve the 90° angle in a semicircle or opposite angles in cyclic quadrilaterals. Read the assertion first independently, then the reason, and finally check if the reason explains the assertion correctly.
What is the difference between angles on the major arc and minor arc?+
For a chord AB, the major arc is the longer arc, and the minor arc is the shorter one. Angles subtended at points on the major arc are smaller, while those on the minor arc are larger. These two angles are supplementary—they add up to 180°.
Can a rectangle be a cyclic quadrilateral?+
Yes, every rectangle is cyclic because opposite angles are 90° each, and 90° + 90° = 180°, satisfying the cyclic property. In fact, any rectangle can be inscribed in a circle with its diagonals as diameters.
How should I practice MCQs for Circles in the last two weeks before boards?+
Solve 10 MCQs daily from NCERT Exemplar, past board papers (2020-2024), and sample papers. Time yourself strictly—10 questions in 10 minutes. Review every wrong answer immediately to understand the mistake, and note down tricky questions for final revision.
Is there negative marking for wrong answers in CBSE Class 10 Mathematics MCQs?+
No, CBSE does not have negative marking in Class 10. If you are unsure, make an educated guess by eliminating clearly wrong options. Never leave an MCQ blank—even a random guess has a 25% chance of being correct.
What is the best way to remember the cyclic quadrilateral property?+
Use the mnemonic 'Opposite angles supplement to 180'. Visualize a quadrilateral inscribed in a circle—opposite corners are farthest apart, so their angles balance out to half a full rotation (180°). Draw one example and label it; that mental image sticks.
How does CBSETUTOR.ai help specifically with Circles MCQs?+
CBSETUTOR.ai lets you upload any Circles MCQ by photo and instantly provides the correct answer, the reasoning, and the theorem applied. If you get an MCQ wrong, the AI explains why each distractor option is incorrect, building your error-recognition skill. It is like having a Maths teacher on call 24×7 for ₹999/month, covering all subjects and classes.

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