Q.

If in two circles, arcs of the same length subtend angles  60   and  75   at the Centre, find the ratio of their radii.


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

Question Image

b

Question Image

c

Question Image

d

Question Image

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

We know that the arc length is l=rθ  .
Converting the given angle into radian, and we have
For 60  ,
θ=60× π 180 = π 3  
For 75  ,
θ=75× π 180 = 5π 12  
Given that their lengths are equal. Then,
l 1 = l 2 r 1 θ 1 = r 2 θ 2 r 1 r 2 = θ 2 θ 1 = 5 12 π 3 = 5 12 × 3 1 = 5 4  
Hence, the correct option is 3.
 
Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon