English

A Circular Wire of Radius 7 Cm is Cut and Bent Again into an Arc of a Circle of Radius 12 Cm. the Angle Subtended by the Arc at the Centre is

Advertisements
Advertisements

Question

A circular wire of radius 7 cm is cut and bent again into an arc of a circle of radius 12 cm. The angle subtended by the arc at the centre is

Options

  • 50°

  • 210°

  •  100°

  • 60°

  • 195°

MCQ
Advertisements

Solution

210°

Length of the arc of radius = Circumference of the circle of radius 7 cm = \[2\pi r = 14\pi\]
Now,
Angle subtended by the arc = \[\frac{\text{ Arc }}{\text{ Radius }} = \frac{14\pi}{12} = \left( \frac{14\pi}{12} \times \frac{180}{\pi} \right)^\circ= 210^\circ\]

 

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Measurement of Angles - Exercise 4.2 [Page 17]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 4 Measurement of Angles
Exercise 4.2 | Q 7 | Page 17

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the radian measure corresponding to the following degree measure:

– 47° 30'


Find the degree measure corresponding to the following radian measure `(use  pi = 22/7)`

`11/16`


A wheel makes 360 revolutions in one minute. Through how many radians does it turn in one second?


In a circle of diameter 40 cm, the length of a chord is 20 cm. Find the length of minor arc of the chord.


Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip describes an arc of length

15 cm


Find the degree measure corresponding to the following radian measure:
\[\frac{9\pi}{5}\]


Find the degree measure corresponding to the following radian measure:
\[- \frac{5\pi}{6}\]


Find the degree measure corresponding to the following radian measure:
\[\left( \frac{18\pi}{5} \right)\]


Find the degree measure corresponding to the following radian measure: 
(−3)c


Find the radian measure corresponding to the following degree measure: 35°


Find the radian measure corresponding to the following degree measure: −300°


The difference between the two acute angles of a right-angled triangle is \[\frac{2\pi}{5}\] radians. Express the angles in degrees.

 

 


One angle of a triangle \[\frac{2}{3}\] x grades and another is \[\frac{3}{2}\] x degrees while the third is \[\frac{\pi x}{75}\] radians. Express all the angles in degrees.


Find the magnitude, in radians and degrees, of the interior angle of a regular octagon.


Find the magnitude, in radians and degrees, of the interior angle of a regular duodecagon.


Let the angles of the quadrilateral be \[\left( a - 3d \right)^\circ, \left( a - d \right)^\circ, \left( a + d \right)^\circ \text{ and }\left( a + 3d \right)^\circ\]
We know: \[a - 3d + a - d + a + d + a - 2d = 360\]
\[ \Rightarrow 4a = 360\]
\[ \Rightarrow a = 90\]
We have:
Greatest angle = 120°
Now,
\[a + 3d = 120\]
\[ \Rightarrow 90 + 3d = 120\]
\[ \Rightarrow 3d = 30\]
\[ \Rightarrow d = 10\]
Hence,
\[\left( a - 3d \right)^\circ, \left( a - d \right)^\circ, \left( a + d \right)^\circ\text{ and }\left( a + 3d \right)^\circ\] are

\[60^\circ, 80^\circ, 100^\circ\text{ and }120^\circ\], respectively.
Angles of the quadrilateral in radians =
\[\left( 60 \times \frac{\pi}{180} \right), \left( 80 \times \frac{\pi}{180} \right) , \left( 100 \times \frac{\pi}{180} \right) \text{ and }\left( 120 \times \frac{\pi}{180} \right)\]
\[\frac{\pi}{3}, \frac{4\pi}{9}, \frac{5\pi}{9}\text{ and } \frac{2\pi}{3}\]
 

 


The angles of a triangle are in A.P. and the number of degrees in the least angle is to the number of degrees in the mean angle as 1 : 120. Find the angles in radians.

 

The number of sides of two regular polygons are as 5 : 4 and the difference between their angles is 9°. Find the number of sides of the polygons.

 

A rail road curve is to be laid out on a circle. What radius should be used if the track is to change direction by 25° in a distance of 40 metres?

 

Find the degree measure of the angle subtended at the centre of a circle of radius 100 cm by an arc of length 22 cm.


If D, G and R denote respectively the number of degrees, grades and radians in an angle, the 


If the angles of a triangle are in A.P., then the measures of one of the angles in radians is


The angle between the minute and hour hands of a clock at 8:30 is


If the arcs of the same length in two circles subtend angles 65° and 110° at the centre, than the ratio of the radii of the circles is


If OP makes 4 revolutions in one second, the angular velocity in radians per second is


The radius of the circle whose arc of length 15 π cm makes an angle of \[\frac{3\pi}{4}\]  radian at the centre is

 

Find the value of tan 9° – tan 27° – tan 63° + tan 81°


If tan θ = `(-4)/3`, then sin θ is ______.


State whether the statement is True or False? Also give justification.

The equality sinA + sin2A + sin3A = 3 holds for some real value of A.


State whether the statement is True or False? Also give justification.

Sin10° is greater than cos10°


State whether the statement is True or False? Also give justification.

One value of θ which satisfies the equation sin4θ - 2sin2θ - 1 lies between 0 and 2π.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×