The length of the minute hand of a clock is 6 cm. Find the area swept by it when it moves from 7:05 p.m. to 7:40 p.m.

 

This question is Similar to Question Ex-12.2-3 - Chapter 12 Class 10

 

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Transcript

Question 24 (Choice 1) The length of the minute hand of a clock is 6 cm. Find the area swept by it when it moves from 7:05 p.m. to 7:40 p.m. Between 7:05 p.m. to 7:40 p.m , The minute hand sweeps 35 minutes Let’s find angle swept Angle swept by minute hand in 1 hour (i.e. 60 minutes ) = 360° Angle swept by minutes hand in 1 minute = (𝟑𝟔𝟎°)/𝟔𝟎 Angle swept by minute hand in 35 minutes = (𝟑𝟔𝟎°)/𝟔𝟎 × 35 = 6° × 35 = 210° Hence, θ = 3210° , r = 6 cm Now, Area swept by minutes hand = Area of sector = θ/360×πr2 = 210/360×22/7×(14)2 = 1/2×22/1 × 6 = 11 × 6 = 66 cm2

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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, Social Science, Physics, Chemistry, Computer Science at Teachoo.