Page 65 - Mathematics Class - X

Viva-Voce

1. Define tangent to a circle.
Ans. A line is said be a tangent to a circle, if it touches the circle at only one point.

2. How many tangents can a circle have?
Ans. A circle can have infinite number of tangents.
3. What is the formula for area of a circle?

Ans. Area of a circle is given by pr .
2
4. Write the relation between radius and diameter of a circle.

Ans. Diameter = 2 × radius
5. How many circles can be drawn taking a point as a centre of circle?
Ans. Infinite circles can be drawn taking a point as a centre of circle.

6. How many tangents can be drawn through a point on the circle?
Ans. One

7. Will it be possible to draw a tangent through a point which is inside the circle?
Ans. No

MCQs

1. An arc of a circle is of length 5p cm and the sector it bounds has an area of 20p cm . The radius of circle is
2
a) 1 cm b) 5 cm c) 8 cm d) 10 cm
2. If the circumference and the area of a circle are numerically equal, then diameter of the circle is
a) p/2 b) 2p c) 2 d) 4

3. The circumference of a circle is 100 cm. The side of a square inscribed in the circle is
a) 50√2 cm b) 100/p cm c) 50√2/p cm d) 100√2/p cm

4. The area of the incircle of an equilateral triangle of side 42 cm is
a) 22√3 cm b) 231 cm c) 462 cm d) 924 cm 2
2
2
2
5. A wire can be bent in the form of a circle of radius 56 cm. If it is bent in the form of a square, then its area
will be
a) 7744 cm b) 6400 cm c) 3520 cm d) 8800 cm 2
2
2
2
Answers: 1. c) 8 cm 2. d) 4 3. b) 50 2 π cm
4. c) 462 cm 5. a) 7744 cm 2
2

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