7th Waste Water Story management Solved Test Paper
Click here CBSE 7th Waste Water Story management Solved questions Click here Assignment Chapter –Waste Water Story Click Here 7th Forest products and Waste management Solved Click Here
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Q.1. How the bats make use of ultrasonic waves to catch their prey? Explain?
Ans. The bat produces high pitched ultrasonic waves. The waves on striking the insect return back, which is heard by the bat. On hearing the echo the bat locates the insect and catches it. Q.2.How does the stethoscope help the doctors in listening to the sound of the patients heart beat? Ans. In a stethoscope, the sound produced within the body of a patient is picked up by a sensitive diaphragm and then reaches the doctor's ear by multiple reflections. Q.3. Explain how defects in a metal block can be detected using ultrasound. Ans. To detect minor cracks or flaws in metal block, ultrasonic waves are allowed to pass through metal blocks and detectors are used to detect the transmitted waves. If there is a crack in metal block, these waves get reflected back Q.4. How is ultrasound used for cleaning? Ans. The object to be cleaned is put in a tank fitted with ultrasonic vibrator. The tank is filled with cleaning solution. As the ultrasonic vibrator is switched on, high frequency vibrations are set up and the dust, grease and dust particles get detached and the object gets thoroughly cleaned. Q.5. What is echo ranging? State any one application of this technique. Solutions for Class 9th Science: Chapter 12 Sound Download File CBSE NCERT IX-Physics for term-II Chapter: Sound key points Read Full Post 1. A solid metallic hemisphere of radius 8 cm is melted and recasted into a right circular cone of base radius 6 cm. Determine the height of the cone.
2. A rectangular water tank of base 11 m × 6 m contains water upto a height of 5 m. If the water in the tank is transferred to a cylindrical tank of radius 3.5 m, find the height of the water level in the tank. 3. How many cubic centimetres of iron is required to construct an open box whose external dimensions are 36 cm, 25 cm and 16.5 cm provided the thickness of the iron is 1.5 cm. If one cubic cm of iron weighs 7.5 g, find the weight of the box. 4. The barrel of a fountain pen, cylindrical in shape, is 7 cm long and 5 mm in diameter. A full barrel of ink in the pen is used up on writing 3300 words on an average. How many words can be written in a bottle of ink containing one fifth of a litre? 5. Water flows at the rate of 10m/minute through a cylindrical pipe 5 mm in diameter. How long would it take to fill a conical vessel whose diameter at the base is 40 cm and depth 24 cm? 6. A heap of rice is in the form of a cone of diameter 9 m and height 3.5 m. Find thevolume of the rice. How much canvas cloth is required to just cover the heap? 7. A factory manufactures 120000 pencils daily. The pencils are cylindrical in shape each of length 25 cm and circumference of base as 1.5 cm. Determine the cost of colouring the curved surfaces of the pencils manufactured in one day at Rs 0.05 per dm2. 8. Water is flowing at the rate of 15 km/h through a pipe of diameter 14 cm into a cuboidal pond which is 50 m long and 44 m wide. In what time will the level of water in pond rise by 21 cm? 9. A solid iron cuboidal block of dimensions 4.4 m × 2.6 m × 1m is recast into a hollow cylindrical pipe of internal radius 30 cm and thickness 5 cm. Find the length of the pipe. 10. 500 persons are taking a dip into a cuboidal pond which is 80 m long and 50 m broad. What is the rise of water level in the pond, if the average displacement of the water by a person is 0.04m3? Answer: 1. 28.44 cm 2. 8.6 m 3. 3960 cm3, 29.7 kg 4. 480000 words 5. 51 minutes 12 sec 6. 4.25m3, 80.61 m2 7. Rs 2250 8. 2 hours 9. 112 m 10. 0.5 cm Mathematics X : Sample Question Papers (March 2013)
Sample_Paper-01 sample -Paper - 02 Sample_Paper-03 sample- paper - 04 sample paper-05 SAMPLE PAPERS Mathematics (Solved) (KV) Sample paper_SA-II_1 sample paper_SA-II-2 Sample paper_SA-II_3 Sample paper_SA-II-4 Sample papers -II- 5 CBSE BOARD New X : Sample Question Papers for Term II (March 2013) By J.Sunil |
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