Class 9 | Science | Chapter 12 |Sound| NCERT Solutions Page 162 1. How does the sound produced by a vibrating object in a medium reach your ear? Answer: When an object vibrates it forces the neighbouring particles of the medium to vibrate.These vibrating particles then forces the particles adjacent to them to vibrate.In this way, vibrations produced by an vibrating … [Read more...] about Chapter 12 Sound
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Chapter 11 Work and Energy
Class 9 | Science | Chapter 11 |Work and Energy| NCERT Solutions Question Answers, Page 148 1. A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case? Answer: Work done = Force × Displacement W= F × … [Read more...] about Chapter 11 Work and Energy
Chapter 9 Force and Law of Motion
Class 9 | Science | Chapter 9 |Force and Law of Motion| NCERT Solutions Question Answers Page 118 1.Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five rupees coin and a one-rupee coin? Answer : Inertia is the measure of mass of the body.The greater is the mass of a body, greater is … [Read more...] about Chapter 9 Force and Law of Motion
Chapter 5 The Fundamental Unit of Life
Class 9 | Science | Chapter 5 |The Fundamental Unit of Life| NCERT Solutions Page 59 1. Who discovered cells, and how? Answer: Cells were discovered in 1665 by an English Botanist, Robert Hooke. He used a primitive microscope to observe cells in a cork slice. 2. Why is the cell called the structural and functional unit of ? Answer: Cell is the smallest unit of … [Read more...] about Chapter 5 The Fundamental Unit of Life
Chapter 4 Structure of the Atom
Class 9 | Science | Chapter 4|Structure of the Atom | NCERT Solutions Page 47 1. What are canal rays? Answer: Canal rays are positively charged radiations. These rays consist of positively charged particles known as protons. They were discovered by Gold stein in 1886. 2. If an atom contains one electron and one proton, will it carry any charge or … [Read more...] about Chapter 4 Structure of the Atom
Chapter 18 Pollution of Air and Water
Class 8 | Science | Ch 16 |Pollution of Air and Water| NCERT Solutions 1. What are the different ways in which water gets contaminated ? Answer: Water gets contaminated by : a) Sewage waste: Waste material from toilet, kitchens, laundry which are discharged in water without proper treatment causes its contamination. b) Industrial dispose: Harmful and poisonous … [Read more...] about Chapter 18 Pollution of Air and Water
Chapter 16 Light
NCERT Solutions for Chapter 16 Light Class 8 1. Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain. Answer: An object becomes visible when light reaches our eyes after being reflected from the object.If we are in dark room, then it is not possible for us to see the objects because no light is reflected from the … [Read more...] about Chapter 16 Light
Chapter 14 Chemical Effects of Electric Current
Class 8 | Science | Ch 12 |Chemical Effects of Electric Current| NCERT Solutions 1. Fill in the blanks. (a) Most liquids that conduct electricity are solutions of , _______ and ________. (b) The passage of an electric current through a solution causes __________ effects. (c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected … [Read more...] about Chapter 14 Chemical Effects of Electric Current
Chapter 13 Sound
Class 8 | Science | Ch 13 |Friction| NCERT Solutions 1. Choose the correct answer. Sound can travel through (a) gases only (b) solids only (c) liquids only (d) solids, liquids and gases. Answer: (d) solids, liquids and gases 2. Voice of which of the following is likely to have minimum frequency? (a) Baby girl (b) Baby boy (c) A man (d) A woman Answer: (c) A … [Read more...] about Chapter 13 Sound
Chapter 12 Friction
Class 8 | Science | Ch 12 |Friction| NCERT Solutions 1. Fill in the blanks. (a) Friction opposes the _____________ between the surfaces in contact with each other. (b) Friction depends on the _____________ of surfaces. (c) Friction produces __________. (d) Sprinkling of powder on the carrom board ________ friction. (e) Sliding friction is ___________ than the static … [Read more...] about Chapter 12 Friction