1. Prove that the lengths of the two tangents drawn from an

external point to a circle are equal.

2. Find the co-ordinates of the centroid of the triangle whose vertices are (-4, 4), (-2, 2) and (6,12)

3. One end of the diameter of a circle is (3, 2) and the centre is

(0, 0). Find the co-ordinates of the other end of the diameter.

4. The observations of a grouped data are x1, x2 and 2x1 and

x1 < x2 < 2 x1. If the mean and median of the data are each
equal to 6. Find the observations.
5. What is a Flow-Chart?
6. Write down the sequence of steps that are to be adopted to solve any given problem by using a computer.
7. State The Basic proportionality Theorem.
8. Find the slope of the line perpendicular to the line 5x-2y+4=0
9. Find the arithmetic mean of first n natural numbers.
10. Expand C.P.U.
11. State and prove the converse of Pythogerean theorm.
12. Find the area of triangle enclosed between the co-ordinate
axes and the line passing through (8,-3) and (-4,12)
13. Find the equation of the line passing through (4, 3) and making intercepts on the coordinate axes whose sum is -1.
14. Using matrix inversion method, solve the equations 2x + 5y -11 = 0 and 4x -3y -9 = 0.
15. Gopal purchased a radio set for Rs. 500 and sold it for Rs. 600. Execute a flow chart using this data to determine the percentage of gain or loss.
**Bits**

I 1. Two circles touch externally, then the number of their common

tangents is

(A) 1 (B) 3 (C) 4 (D) 2

2. The A.M. of a+2, a, a-2 is

(A) a+2 (B) a (C) a-2 (D) 3a

3. A minute hand of a table clock is 3 cm long, How far its tip

move in 20 minutes

(A) 3 cm (B) 9 cm (C) 22 / 7 cm (D) 44 / 7 cm [ ]

4. Vaccum tubes are used in generation computers.

(A) fourth (B) first (C) second (D) Third [ ]

II. Fill in the blanks with suitable answers.

5. The slope of the line joining the points (2, -5) and (8, 1) is

-----

6. The number of circles drawn through three non-collinear

points is ----

7. The mode of 4, 5, 6, 7, 8, 9, 6 is -----

8. An example for input unit is -----

9. All the parts of a computer are controlled by ----

10. If the transpose of a given matrix is equal to its additive

inverse, that matrix is called ----