CBSE ADDA

ASSIGNMENT AREAS RELATED TO CIRCLES CLASS X : 1. The radius of the circle is 3 m. What is the circumference of another circle, whose area is 49 times that of the first? 2. Two circles touch externally. The sum of their areas is 130 p sq. cm and the distance between their centres is 14 cm. Find the radii of the circles. 3. A wire when bent in the form of an equilateral triangle encloses an area of 121 √3 cm2 . If the same wire is bent in the form of a circle, find the area of the circle. 4. The area enclosed between the two concentric circles is 770 cm2. If the radius of the outer circle is 21 cm, calculate the radius of the inner circle. 5. A wheel of diameter 42 cm, makes 240 revolutions per minute. Find : (i) the total distance covered by the wheel in one minute. (ii) the speed of the wheel in km/hr. Read more » 10th Maths SA-2 Chapter  Quick links Quadratic Equations Circles Co-ordinate Geometry Arithmetic Progression

Multiple type questions 1).what type of wave is sound wave? (a) radio waves (b) electro magnetic wave (c) mechanical wave (d)transverse wave 2.SONAR works on principle of (a) echo (b)resonance(c)particle nature of wave (d) none 3. Loudness depends on (a) wave length (b) frequency(c) amplitude (d)intensity 4. Pitch increases with increase in (a) energy of sound (b) frequency (c) wave length (d) amplitude 5. speed of sound greatest in (a) milk (b) wood(c) iron (d) air 6. The sound whose frequency is between 20 Hz to 20000 Hz is (a)infrasonic wave (b) audible sound (c)ultrasonic wave (d) radio waves Very Short Answer questions 1. What is echo? 2. what are conditions necessary to hear echo? 3. What is SONAR ? Give its use? 4. How density of mediam affect speed of sound? 5. What is pitch of sound? 6. What is amplitude of sound waves? 7. What is resonance? 8. What is sonometer? 9. Define the terms

Work When a force applied on an object and the object moves in the direction of force, we say that the force has done work on the object. Conditions essential for work to be done are :   1. Some force must act on the object   2. Object move in the direction of force   Hence, the product of the force and the distance moved measures work done.   W = F x S   Where W is the work done, F is the force applied and S is the distance covered by the moving object.  Work is the product of the magnitudes of the force and the displacement, and direction is not taken into account. So work is a  scalar  quantity What is the work done when the force on the object is zero? The work done is zero What would be the work done when the displacement of the object is zero? The work done is zero A force of 5 N is acting on an object. The object is displaced through 2 m in the direction of the force.  If the force acts on the object all through the displacement, what is the work done in this case? Work do

10th Maths Test Paper Q1 A ladder 15 m long just reaches the top of a vertical wall. If the ladder makes an angle of 60°with the wall, find the height of the wall. (7.5 √3 ) Q 2 A pole 12 m high casts a shadow 4 √3 m long on the ground. Find the angle of elevation (60°) Q 3 The angle of elevation of the top of a tower from a point on the ground is 30° if on walking 30m towards the tower, the angle of elevation becomes 60°.Find the height of the tower.(15√3 ) Q 4 An observer 1.5m tall is 20.5m away from a tower 22m high. Determine the angle of elevation of the top of the tower from the eye of the observer. (45°) Q 5 An aero plane when flying at a height of 5000m from the ground passes vertically above another aero plane at an instant when the angles of the elevation of the two planes from the same point on the ground are 60° and 45° respectively. Find the vertic