Jagranjosh presents CBSE Class 9th Science Solved Practice Paper for SA – I for the academic session 2016-17. This solved practice paper is specially prepared at jagranjosh.com after the brief analysis of previous year SA ‒ I question papers.
About CBSE Science Solved Practice Paper for SA – I: 2016-17
Most of the schools set CBSE Class 9th Science SA – I papers as per the examination pattern issued by CBSE board.
However, level of questions in the question paper varies from school to school. Despite the variations in level of questions asked in the question papers set by different CBSE schools, there are some common questions which are asked in various schools frequently.
This solved practice paper gives you an idea of such types of questions. All the questions in practice paper are provided with detailed explanation.
Importance of CBSE Class 9th Solved Practice Paper 2016 -2017:
This Science SA – I solved practice paper is set as per the latest CBSE exam pattern. The questions asked in this paper will give you a fair idea of the important topics to be studied for SA-I: 2016-17 and help you score optimum.
Unique solutions to all the questions are provided. These solutions will give you a clear idea about what and how much must be written in the Class 9th Science SA – I examination 2016 – 17 to fetch you the maximum score.
After going through this solved practice paper you will:
• understand the latest examination pattern
• learn time management
• know important questions likely to be asked in SA – I Science exam
• know how to give proper explanations of the questions
Some of the sample questions from the solved practice paper are:
Q. List two processes from which it may be concluded that the particles of a gas move continuously.
Solution:
Spraying perfume in a room and standing at a distance. You will still smell the perfume even from afar. When your mother prepares hot food, you can smell the delicious scent from your room as well.
Q. Define momentum and give its SI unit.
Solution:
The momentum of an object is defined as the product of its mass and velocity. The SI unit of momentum is kilogram meter per second (kg m s‒1).
Q. In which way location of chlorophyll is different in eukaryotes as compared to prokaryotic photosynthetic bacteria?
Solution:
The chlorophyll is present in the mesophyll tissue of the leaf in eukaryotes .It is a pigment present in the chloroplast. Whereas, in photosynthetic prokaryotic bacteria, the chlorophyll is associated with membranous vesicles (bag like structures).
Q. Why the cell is called the structural and functional unit of life?
Solution:
It is called so because the body’s major organs and tissues, all are made up of cells. They are also capable of performing all the biological activities of the living body.
Q. What is fractional distillation? How is it different from distillation? Give its one use.
Solution:
Fractional distillation is the isolation of volatile components of varying boiling points in a mixture by slowly increasing the temperature and the separating the collection of each component. Whereas, distillation is the process of separating the components from a liquid mixture by evaporation and condensation.
Use of fractional distillation: Various petroleum products are separated from the crude oil with the help of fractional distillation.
Q. What determines the state of a substance? Suggest a method to liquefy gases. Water droplets are observed on the outer surface of a glass tumbler containing ice cold water. Give reason.
Solution:
The physical state of a substance depends on intermolecular space and intermolecular force of attraction which in turn depends on pressure, volume and temperature.
Gas can be liquefied by increasing pressure and decreasing temperature.
Water droplets are observed on the outer surface of a glass tumbler containing ice cold water due to condensation. If the liquid inside the glass is cold then, the water vapour present in the atmosphere near the glass surface condense and sticks to it in the form of water droplets.
Q. (a) Identify heterogeneous mixture from the following: Air, Soda water, Soap solution, Brass
(b) Write two components of a colloidal solution. Give two examples of a colloidal solution.
Solution:
(a) Brass is the heterogeneous mixture only rest are homogenous. A heterogeneous mixture is made of different substances that remain physically separate.
(b) The components of a colloidal solution are dispersed phase and dispersion medium. The two examples of colloidal solution are milk and blood.
Q. Write four components of phloem. Which one of them is most important and why?
Solution:
Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma.
Sieve tubes are very important because they are living cells unlike xylem vessels. They are crucial because they transport carbohydrates, primarily sucrose in the plant. This is an important aspect from the growth and development view.
Q. Explain mixed cropping? What are the criteria for selecting crops for mixed farming?
Solution:
Mixed cropping is the practice of growing two or more crops simultaneously on the same area. This procedure often leads to fertility of soil.
There are many criteria for crop selection for mixed farming:
a. One crop is shallow rooted and other deep rooted.
b. One crop requires less water than other.
c. One crop requires fewer nutrients than other.
d. One crop is of long duration and other of short duration.
Q. (a) "We can easily move our hands in air but not through any solid material". Justify the statement giving any three possible reasons.
(b) State reasons:
(i) Temperature of water remains constant during boiling.
(ii) Increase in humidity in air decreases the rate of evaporation.
Solution:
(a)We can easily move our hands in air but not through any solid material because:
• The molecules in solid material are tightly packed, so movement is not possible. Air is a gas; there is lot of free space, so movement is effortless.
• The density of solid is more and air is less.
• The particles of solid cannot be displaced due to greater force of attraction between the particles.
(b) (i) During boiling when further heat is supplied, the water undergoes phase transformation. Evaporation occurs i.e. water turns into vapour. The temperature is constant during the whole time.
(ii) Because there is more water, in vapour form, in the air so it is harder for even more to evaporate compared to when there is no vapour - humidity - in the air. The dryer the air is, i.e. the lower the relative humidity is, the more evaporation will occur in the air right above the water. Therefore, increase in humidity in air decreases the rate of evaporation.
