Chapter 11 Human Eye and Colourful World
Chapter 11 Human Eye and Colourful World In Text Book Questions Question 1. What is meant by power of accommodation of the eye ? (CBSE Sample Paper 2010, 2012, 2014, 2015, 2016, 2017) Answer: The ability of the eye lens to adjust its focal length to see nearby and distant objects clearly. Question 2. A […]
Chapter 10 Light Reflection and Refraction
Chapter 10 Light Reflection and Refraction In Text Book Questions Question 1. Define the principal focus of a concave mirror. Answer: A point on the principal axis where the parallel rays of light after reflecting from a concave mirror meet. Question 2. The radius of curvature of a spherical mirror is 20 cm. What is […]
Chapter 9 Heredity and Evolution
Chapter 9 Heredity and Evolution In Text Questions Question 1. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same species, which trait is likely to have arisen earlier ? Answer: In asexually reproducing population, there is no reshuffling of […]
Chapter 8 How do Organisms Reproduce
Chapter 8 How do Organisms Reproduce In Text Questions Question 1. What is the importance of DNA copying in reproduction ? (CCE 2011, 2015) Answer: DNA carries hereditary information not only for controlling cellular functions but also all the structural and functional traits of organism. It is because of the latter that single celled zygote […]
Chapter 7 Control and Coordination
Chapter 7 Control and Coordination In Text Questions Question 1. What is the difference between reflex action and walking ? Answer: Reflex Walking/Voluntary 1. Origin. Reflex action is inborn and present in an individual right from birth. 2. Control. It is automatic. An individual cannot control it. 3. Intensity. It cannot be changed. 4. Value. It has survival and protective […]
Chapter 6 Life Processes
Chapter 6 Life Processes In text Questions Question 1. Why is diffusion insufficient to meet the oxygen requirement of multicellular organisms like us ? Answer: Every living cell requires oxygen for performing cellular respiration. In unicellular organisms (e.g., Amoeba), the single cell is in direct contact with environment. Oxygen passes into it through diffusion. In […]
Chapter 5 Periodic Classification of Elements
Chapter 5 Periodic Classification of Elements Text Book Questions Question 1. Did Doberiener’s triads also exist in the columns of Newlands’ octaves ? Compare and find out. Answer: Yes, some of the Doberiener’s triads did exist in the columns of Newlands’ octaves. For example, Question 2. What were the limitations of Doberiener’s triads ? Answer: […]
Chapter 4 Carbon and its Compounds
Chapter 4 Carbon and its Compounds In Text Book Questions Question 1. What would be the electron dot structure of carbon dioxide which has the formula CO2 ? Answer: The atomic number (Z) for carbon is six and its electronic configuration is 2, 4. Carbon has four valence electrons. Each oxygen atom (Z = 8) has […]
Chapter 3 Metals and Non-metals
Chapter 3 Metals and Non-metals Question 1. Give example of a metal which (a) is a liquid at room temperature (b) can be easily cut with a knife (c) is the best conductor of heat (d) is the poorest conductor of heat. Answer: (a) Mercury (b) Sodium (c) Silver (d) Lead. Question 2. Explain the […]
Chapter 2 Acids Bases and Salts
Chapter 2 Acids Bases and Salts Question 1. You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution respectively. If you are given only red litmus paper, how will you identify the contents of each test tube ? Answer: […]