Two tangents PA and PB are drawn to a cirlce with centre O from

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsShort Answer Type

251. Two tangents TP and TQ are drawn from an external point T to a circle with centre O, as shown in figure. If they are inclined to each other at angle of 70°, then what is the value of ∠POQ?


115 Views

252. In the figure given below, PA and PB are tangents to the circle drawn from an external point P. CD is a third tangent touching the circle at Q. If PB = 10 cm and CQ = 2 cm, what is the length of PC?  


2510 Views

253. The length of tangent from a point A at a distance of 5 cm from the centre of the circle is 4 cm. What will be the radius of the circle?


90 Views

254. What is the distance between two parallel tangents of a circle of the radius 4 cm?
1261 Views

Advertisement
255. Two tangents TP and TQ are drawn from an external point T to a circle with centre O, as shown in Fig. If they are inclined to each other at an angle of 100°, then what is the value of ∠POQ? 


103 Views

256. In figure 2, if ∠ATO = 40°, find ∠AOB.


439 Views

Advertisement

257. Two tangents PA and PB are drawn to a cirlce with centre O from an external point P. Prove that ∠APB = 2∠OAB.



Given : A circle with centre O, an external point P and two tangents PA and PB to the circle, where A and B are points of contact (Fig. 10.36A).
To Prove : ∠APB 2∠OAB
Proof : Let ∠APB = 9 ∴ PA = PB
[∴ Tangents from an ext. pt. are equal]

rightwards double arrow  increment APB is ab isosceles triangle

rightwards double arrow space space space space space space space space space space angle PAB space equals space angle PBA
space space space space space space space space space space space space space space space space space space space space space space space space equals 1 half left parenthesis 180 degree minus angle APB right parenthesis
space space space space space space space space space space space space space space space space space space space space space space space space equals 1 half left parenthesis 180 degree minus straight theta right parenthesis
space space space space space space space space space space space space space space space space space space space space space space space space equals space 90 degree minus 1 half straight theta
But space space space space space space space space space space angle OAP space equals space 90 degree
space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space left square bracket because space Radius space is space perpendicular space to space the space tangent right square bracket
therefore space space space space space space space angle OAB space equals space angle OAP space minus space angle PAB
space space space space space space space space space space space space space space space space space space space space space equals space 90 degree minus open parentheses 90 degree minus 1 half straight theta close parentheses
space space space space space space space space space space space space space space space space space space space space space space equals space 1 half straight theta equals 1 half angle APB
space space space space space space space space space space space space space space space space space space space space space

Hence, ∠APB = 2 ∠OAB. Proved.

4819 Views

Advertisement
258. O is the centre of two concentric circles of radii 4 cm and 6 cm. PT and PS are tangents to the larger circle and smaller circle respectively from an external point P.PT = 10 cm, find the length of PS.
252 Views

Advertisement
259. A circle is inscribed in a ΔABC, having sides 8 cm, 10 cm, and 12 cm, as shown in Fig. Find AD, BE and CF.

117 Views

260. In figure, a circle touches all the four sides of a quadrilateral ABCD/ whose sides AB = 6 cm, BC = 7 cm and CD = 4 cm. Find AD. 


299 Views

Advertisement