JEE Main 2023 · MathsNumerical answerNumerical valueMediumMulti-step

JEE Main 8 April 2023, Shift 1, Maths Q27

Question 27 of 90 in this shift, Maths question 27 of 30, Section B.

Consider a circle

C_1:x^2+y^2-4x-2y=\alpha-5

. Let its mirror image in the line

y=2x+1

be another circle

C_2:5x^2+5y^2-10fx-10gy+36=0

. Let

r

be the radius of

C_2

. Then

\alpha+r

is equal to __________.

Official answer

NTA final key.

Chapter: Conic Sections
Topic: General Conic Section
Idea tested: Condition for a Circle

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Asked 5× in all

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.