CBSE EXAMINATION PAPER-2022
SCIENCE
(Solved)
General Instructions :
Read the following instructions carefully and follow them :
- This question paper contains 16 questions. All questions are compulsory.
- This question paper is divided into 3 sections.
- Section A – questions number 1 to 4 are case based questions
- Section B – questions number 5 to 13 are very short answer
- Section C – questions number 14 to 16 are short answer
- There is no overall choice given in the question paper. However, an internal choice has been provided in few questions.
- Use of calculator is NOT allowed.
Section A
A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminum rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions:
Draw the patter of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
Section B
"Carbons prefers to share its valence electrons with other atoms of carbon or with atoms of other elements rather than gaining or losing the valence electrons in order to attain noble gas configuration." Give reasons to justify this statement.
The atomic number of an element 'X' is 11.
(i) Write the electronic configurations of X and find its valency.
(ii) Write the formula and nature of its oxide.
Give reasons :
(i) Placenta is Extremely essential for foetal development.
(ii) Uterine lining becomes thick and spongy after fertilisation.
(a) Name the reproductive and non-reproductive parts of bread mould (Rhizopus).
(b) List any two advantages of vegetative propagation.
Name the reproductive parts of an angiosperm. Where are these parts located ? Explain the structure of its male reproductive part.
What is puberty ? Mention any two changes that are common to both boys and girls in early teenage years.
When is the force experienced by a current - carrying straight conductor placed in a uniform magnetic field.
(i) Maximum;
(ii) Minimum ?
In the following food chain only 2J of energy was available to the peacocks. How much energy would have been present in Grass ? Justify your answer.
GRASS → GRASS HOPPER → FROG → SNAKE → PEACOCK
Energy at snake level = 2J * 10 = 20J.
Energy at frog level = 20J * 10 = 200J.
Energy at grasshopper level = 200J * 10 = 2000J.
Energy at grass (producer) level = 2000J * 10 = 20000J.
Therefore, energy present in grass would be 20000J because at each level energy decreases by 90 percent due to loss in form of heat and other processes.
(a) What is meant by garbage ? List two classes into garbage is classified.
(b) What do we actually mean when we say that the "enzymes are specific in their action"?
Section C
Consider the following organic compounds:
(a) Name the functional group present in their compounds.
(b) Write the general formula for the compounds of this functional group.
(c) State the relationship between these compounds and draw the structure of any other compound having similar functional group.
(b) The general formula for compounds containing the aldehyde group is R-CHO, where R represents a hydrocarbon group or hydrogen.
(c) The compounds are related as homologous series, meaning they differ by a -CH2- unit.
Another compound with the aldehyde group is ethanal. Its structure is CH3-CHO, which has a methyl group attached to the aldehyde functional group.
Structure of ethanal: CH3-C(=O)-H.
(a) State Ohm's Law. Represent it mathematically.
(b) Define 1 Ohm.
(c) What is the resistance of a conductor through which a current of 0.5 A flows when a potential difference of 2 V is applied across its ends?
(b) 1 Ohm is defined as the resistance of a conductor when a potential difference of 1 volt across its ends produces a current of 1 ampere through it. That is, 1 ohm = 1 volt / 1 ampere.
(c) Given, current I = 0.5 A and potential difference V = 2 V. Using Ohm's Law, resistance R = V / I = 2 V / 0.5 A = 4 ohms. Therefore, the resistance of the conductor is 4 ohms.
(a) What is the meaning of electric power of an electric device ? Write its SI unit.
(b) An electric kettle of 2kW is used for 2h. Calculate the energy consumed in
(i) kilowatt hour and
(ii) joules.
(b) Given power of kettle P = 2 kW, time t = 2 hours
(i) Energy consumed in kilowatt hour = Power * Time = 2 kW * 2 h = 4 kW h
(ii) We know that 1 kW h = 1000 watt * 3600 seconds = 3 600 000 joules
Therefore, energy consumed in joules = 4 kW h = 4 * 3 600 000 J = 14 400 000 joules or 1.44 * 107 J
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