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An arc PQ of a circle substends and angl...

An arc PQ of a circle substends and angle 1.5 radian at its centre O. Let the radius of the circle is 100cm. If l is arc length `overset(frown)(PQ)` (in cms) and m is area of sector POQ (in `cms^(2))`, then `(m)/(l)` is

A

50

B

10

C

15

D

20

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will calculate the arc length \( l \) and the area of sector \( m \), and then find the ratio \( \frac{m}{l} \). ### Step 1: Calculate the arc length \( l \) The formula for the length of an arc is given by: \[ l = r \cdot \theta \] where \( r \) is the radius and \( \theta \) is the angle in radians. Given: - Radius \( r = 100 \) cm - Angle \( \theta = 1.5 \) radians Substituting the values: \[ l = 100 \cdot 1.5 = 150 \text{ cm} \] ### Step 2: Calculate the area of sector \( m \) The formula for the area of a sector is given by: \[ m = \frac{1}{2} r^2 \theta \] Substituting the values: \[ m = \frac{1}{2} \cdot (100)^2 \cdot 1.5 \] Calculating \( (100)^2 \): \[ (100)^2 = 10000 \] Now substituting this back into the area formula: \[ m = \frac{1}{2} \cdot 10000 \cdot 1.5 = 5000 \cdot 1.5 = 7500 \text{ cm}^2 \] ### Step 3: Calculate the ratio \( \frac{m}{l} \) Now we have: - \( m = 7500 \text{ cm}^2 \) - \( l = 150 \text{ cm} \) Calculating the ratio: \[ \frac{m}{l} = \frac{7500}{150} \] Simplifying: \[ \frac{7500}{150} = 50 \] ### Final Answer Thus, the value of \( \frac{m}{l} \) is \( 50 \).
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