SAMPLE QUESTION PAPER – 1
Class – X
Session: 2021-22 (TERM II)
Subject: Science
Time Allowed: 120 minutes Maximum Marks: 40
General Instructions:
1. All questions are compulsory.
2. The question paper has three sections and 15 questions. All questions are compulsory.
3. Section–A has 7 questions of 2 marks each; Section–B has 6 questions of 3 marks each; and Section–C has 2 case-based questions of 4 marks each.
4. Internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
SECTION A
1. a) What are homologous structures? Give an example.
Homologous structures are structures having a similar origin, similar development, similar internal structure and basic plan but showing different external form and function. Example – Forelimbs of mammals, birds, reptiles and amphibians.
b) Is it necessary that homologous structures always have a common ancestor?
Yes, it is necessary that they have a common ancestor, since otherwise there cannot be any similarity in basic plan, origin or internal structure.
2. An element has the atomic number 12.
a) Is “M” a metal or a non-metal? Give a reason in support of your answer.
M is a metal. M is metal as it has 2 valence electrons in the outermost shell and it loses the 2 electrons to form the +2 positive charge and hence it gains metallic character
b) Write the formula and nature (acidic/basic) of the oxide for M.
MO. Basic oxide
3. The wire in the figure below is being moved downwards through the magnetic field, so as to produce induced current. What would be the effect of
a) moving the wire at a higher speed?
The induced current moves at a higher speed.
b) moving the wire upwards rather than downwards?
The induced current is reversed.
OR
State the purpose for which the following RULES ARE USED
a) Right-hand thumb rule
To find the direction of current and magnetic field
b) Fleming’s left-hand rule
Fleming’s left hand rule gives the direction of magnetic force acting on a conductor.
4. Give reasons for the following:
a) How does the supply of air affect the combustion of saturated hydrocarbons?
If air supply is not sufficient, saturated hydrocarbons give yellow sooty flame
b) Why are holes provided at the bottom of a Bunsen burner?
Holes let the supply of air to be adjusted for complete combustion.
5. Suggest one word for each of the following statements/ definitions:
a) The physical and biological world where we live in
Environment/biosphere
b) Each level of the food chain where transfer of energy takes place
Trophic level
OR
Suggest one word for each of the following statements/ definitions:
a) The physical factors like temperature, rainfall, wind, and soil of an ecosystem
Abiotic factors
b) Organisms that depend on the producers either directly or indirectly for food
Consumers/heterotrophs
6. Give a reason for the following:
a) Why are metals good conductors of electricity whereas glass is a bad conductor of electricity?
Metals are good conductor of electricity as they have low resistivity and they have free electrons. Glass is a bad conductor of electricity as it has high resistivity and have no free electrons.
b) Why are alloys commonly used in electrical heating devices?
As we know alloys have high resistivity and high melting point as compared to pure metals. … So alloys cannot easily burn or oxidize at higher temperature. Now as we want higher temperature in heating devices so we use alloys in heating devices.
7. Reproduction is one of the most important characteristics of human beings. Give two reasons in support of the statement.
(i) Reproduction helps in increasing the number of members of a population.
(ii) By replacing the dead members with the new ones, it minimizes the risk of extinction of a species.
(iii) It brings about variations in species, thus, leading to their evolution.
OR
Suggest two contraceptive methods to control the size of the human population which is essential for the health and prosperity of a country. State the basic principle involved in each.
(i) Barrier method: – In this method, the fertilisation of the ovum and the sperm is prevented with the help of barriers such as a condom.
(ii) Oral contraceptive method: – In this method, tablets or drugs are taken orally to prevent fertilisation.
SECTION B
8. An element has the same number of electrons in I and IV shells and in the II and III shells.
a) Write down the electronic configuration of the element.
Electronic configuration
K L M N
2 8 8 2
b) Write the group number and period to which it belongs.
Group 2 [because valence shell contains 2 electrons] period 4th (as the number of shells are 4]
c) What is the valency of the element?
Valency of the element is 2.
OR
An element Y has a total of three shells, with six electrons in its valence shell.
a) What will be the atomic number of this element?
Atomic Number – 16
b) In which period will you find this element?
Period – 3
c) Name another element that belongs to the same group as this element.
Oxygen
9. While teaching the chapter “Our Environment” the teacher stressed the harmful effects of the burning of fossil fuels, plastic paper, etc. The students noticed the extensive use of plastic and polythene in daily life, which can be avoided and the surroundings can be kept clean. They decided to make their school “Plastic and Polythene” free and motivated each other for its minimum use.
a) Why should the use of polythene and plastic be reduced in daily life?
Polythene and plastics are synthetic materials and are non-biodegradable. Hence, they would cause pollution and damage the environment.
b) In what way would the students have avoided the use of plastic and polythene in their school?
Carry your tiff-in and lunch pack in steel containers.
Encourage the students to use cloth bags/jute bags instead of using plastic bags
c) How the students would have motivated each other for the success of their decision.
By spreading awareness in the form of class plays, Speeches in Morning Assembly, Class Discussions, Display Boards etc.
10. When ethanol reacts with ethanoic acid in the presence of conc. H2SO4, a substance with a fruity smell is produced. Answer the following:
a) State the class of compounds to which the fruity-smelling compounds belong.
esters
b) Write the chemical equation for the reaction and the chemical name of the product formed.
ethyl ethanoate
c) State the role of conc. H2SO4 in this reaction.
It acts as a dehydrating agent.
11. What is the difference between a direct current and an alternating current? How many times does AC use in India change direction in one second?
Direct current always flows in one direction but the alternating current reverses its direction periodically. The frequency of AC in India is 50 Hz and in each cycle it alters direction twice. Therefore, AC changes direction 2 x 50 = 100 times in one second.
12. In a pea plant, find the contrasting trait if
a) the position of the flower is terminal
Axial
b) the flower is white in colour
Violet
c) The shape of the pod is constricted
Full
OR
a) If we cut the tail of a mouse, will the tail occur in the next generation of that mouse? Give reason to support your answer?
Yes, the next generation of the mouse will have tail because removal of the tail cannot change the generic makeup of the mouse.
b) What are the features that Archaeopteryx had in common with the reptiles?
(i) The presence of a long tail.
(ii) The presence of teeth.
13. Fill in the blanks:
a) The most important safety method used for protecting home appliances from short circuiting or overloading is _________________.
b) Genes that are not expressed are called ____________.
c) The change in the frequency of some genes in a population that provides diversity without any survival disadvantage is called ___________.
a) using fuse
b) recessive
c) genetic drift
SECTION C
14. The reproductive parts of angiosperms are located in a flower. The different parts of a flower are sepals, petals, stamens, and carpels. Stamens and carpels are the reproductive parts of a flower that contain the germ – cells. The flower may be unisexual (papaya, watermelon) when it contains either stamens or carpels or bisexual (Hibiscus, mustard) when it contains both stamens and carpels. Stamen is the male reproductive part and it produces pollen grains that are yellowish in color. Carpel is present in the center of a flower and is the female reproductive part.
a) Where are the plant’s sex organs located?
flower
b) What is the function of a flower?
reproduction
c) Where are the male and female gametes formed in flowering plants?
male gametes – anther; female gametes – ovary
15. An electric lamp, whose resistance is 20 ohm, and a conductor of 10-ohm resistance are connected to a 6V battery. Use this information to answer the following questions:
a) What is the formula for Ohm’s law?
V = IR
b) Calculate the total resistance of the circuit.
30 ohm
c) Calculate the potential difference across the conductor and the electric lamp respectively. 2V and 4V