If the circumference of a circle increases from 2π to 4 π then its area _____ the original area
(a) Half (b) Double (c) Three times (d) Four times

CBSE Class 10 Sample Paper for 2022 Boards - Maths Basic [MCQ]
CBSE Class 10 Sample Paper for 2022 Boards - Maths Basic [MCQ]
Last updated at Dec. 16, 2024 by Teachoo
Transcript
Question 25 If the circumference of a circle increases from 2π to 4 π then its area _____ the original area (a) Half (b) Double (c) Three times (d) Four times Now, Old Circumference = 2π 2 Γ π Γ Old Radius = 2π Old Radius = ππ/ππ Old Radius = 1 Now, (π΅ππ π¨πππ)/(πΆππ π¨πππ)=(π(πππ€ π ππππ’π )^2)/(π(πππ π ππππ’π )^2 ) New Circumference = 4π 2 Γ π Γ New Radius = 4π New Radius = ππ/ππ NEw Radius = 2 =(π Γ π^π)/(π Γ π^π ) =(π Γ 4)/(π Γ 1) = 4 Thus, New Area = 4 Γ Old Area So, the correct answer is (d)