Book Online Demo
Check Your IQ
Try Test

Courses

Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course

Q.

You are required to create a model of a circular wall clock and paste the numbers from 1 to 12 on its dial. What is the angle made at the center between 3 and 7? Find the area of this region, if the length of the minute hand of the clock is 21 cm.


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

140 °  and 1252 c m 2  

b

130 °  and 352 c m 2  

c

120 °  and 462 c m 2  

d

150 °  and 587 c m 2   

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

Given that we have to create a model of a circular wall clock and paste the numbers from 1 to 12 on its dial.
We have to find the angle made at the center between 3 and 7 and have to find the area of this sector.
The expression to find the area of a sectors, A= θ 360 ° π r 2  . Here r   is the radius.
The required figure geometry is shown below,
     Question ImageThe length of a minute hand of a clock is given as Question Imagecm .
There are 12 points and the angle formed by every pair of points at the center will be some x o  .
We know that the sum of the angle that lie between pair of numbers is 360 o  .
Thus, the angle that is formed by each of the twelve numbers on the clock is,  x o = 360 ° 12 ⇒ x o = 30 °  
Between 3 and 7, there are 4 such pairs.  Then, the angle between 3 to 7 is,
θ=4× 30 ° ⇒θ= 120 °  
 So, the area swept by the minute hand between 3 to 7  is,  Question ImageThe value for central angle is 120 °   and the area of the region is 462 c m 2  .
Therefore, the correct option is 3.
 
Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
whats app icon
You are required to create a model of a circular wall clock and paste the numbers from 1 to 12 on its dial. What is the angle made at the center between 3 and 7? Find the area of this region, if the length of the minute hand of the clock is 21 cm.