If the circumference of a circle increases from 2Ο€ to 4 Ο€ then its area _____ the original area

(a) Half Β  (b) Double Β (c) Three times Β  (d) Four times

Ques 25 (MCQ) - If circumference of a circle increases from 2Ο€ to 4Ο€ - CBSE Class 10 Sample Paper for 2022 Boards - Maths Basic [MCQ]

part 2 - Question 25 - CBSE Class 10 Sample Paper for 2022 Boards - Maths Basic [MCQ] - Solutions of Sample Papers for Class 10 Boards - Class 10

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Question 25 If the circumference of a circle increases from 2πœ‹ to 4 πœ‹ then its area _____ the original area (a) Half (b) Double (c) Three times (d) Four times Now, Old Circumference = 2πœ‹ 2 Γ— πœ‹ Γ— Old Radius = 2πœ‹ Old Radius = πŸπœ‹/πŸπœ‹ Old Radius = 1 Now, (π‘΅π’†π’˜ 𝑨𝒓𝒆𝒂)/(𝑢𝒍𝒅 𝑨𝒂𝒆𝒂)=(πœ‹(𝑁𝑒𝑀 π‘…π‘Žπ‘‘π‘–π‘’π‘ )^2)/(πœ‹(𝑂𝑙𝑑 π‘…π‘Žπ‘‘π‘–π‘’π‘ )^2 ) New Circumference = 4πœ‹ 2 Γ— πœ‹ Γ— New Radius = 4πœ‹ New Radius = πŸ’πœ‹/πŸπœ‹ NEw Radius = 2 =(𝝅 Γ— 𝟐^𝟐)/(𝝅 Γ— 𝟏^𝟐 ) =(πœ‹ Γ— 4)/(πœ‹ Γ— 1) = 4 Thus, New Area = 4 Γ— Old Area So, the correct answer is (d)

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo