Advertisements
Advertisements
प्रश्न
Length of tape required to cover the edges of a semicircular disc of radius 10 cm is ______.
पर्याय
62.8 cm
51.4 cm
31.4 cm
15.7 cm
Advertisements
उत्तर
Length of tape required to cover the edges of a semicircular disc of radius 10 cm is 51.4 cm.
Explanation:
In order to find the length of tape required to cover the edges of a semi-circular disc, we have to find the perimeter of semi-circle
From the above figure it is clear that,
Perimeter of semi-circle = Circumference of semi-circle + Diameter
∵ Circumference of semi-Circle = `(2πr)/2`
= π × r
= `22/7 xx 10`
= `220/7`
= 31.4 cm
∴ Total tape required = 31.4 + 2 × 10 ...[∵ Diameter = 2 × radius]
= 51.4 cm
APPEARS IN
संबंधित प्रश्न
An elastic belt is placed round the rim of a pulley of radius 5 cm. One point on the belt is pulled directly away from the centre O of the pulley until it is at P, 10 cm from O. Find the length
of the belt that is in contact with the rim of the pulley. Also, find the shaded area.
Four cows are tethered at four corners of a square plot of side 50m, so that’ they just cant reach one another. What area will be left ungrazed.
Find the length of the arc of a circle of diameter 42 cm which subtends an angle of 60° at the centre.
The circumference of a circle is 39.6 cm. Find its area.
The radii of two concentric circles are 19 cm and 16 cm respectively. The area of the ring enclosed by these circles is
A bucket is raised from a well by means of a rope wound round a wheel of diameter 35 cm. If the bucket ascends in 2 minutes with a uniform speed of 1.1 m per sec, calculate the number of complete revolutions the wheel makes in raising the bucket.
The speed of the car is 66 km/hour. If each wheel of the car is 140 cm in diameter, find the number of revolutions made by each wheel per minute.
The diameter of a right circular cylinder is 12 m and the slant height is 10 m. Find its curved surface area and the total surface area .
The radius of two circles are in the ratio 3 : 5, find the ratio between their circumferences.
Find the area of a circle whose circumference is 22 cm.
