 Table of Content

## Science Class 10 Term 2 Answer Key

CBSE Class 10 Science Answer Key for Term 2 Exam 2022: CBSE has conducted the Class 10 Science Exam on 10th May 2022 (Tuesday) and now the students, as well as their parents, must be eager to know the level of performance of their kids as the Term 2 Science Exam concludes. The students can follow the Class 10 Science Term 2 Answer Key 2022 which will be discussed in detail here as per our faculty. We will be providing authentic and explained answers to each question asked in the Class 10 Term 2 Science Examination. Bookmark this page and do keep refreshing the page to get the correct answers for each question asked in today's exam.

## Class 10 Science Answer Key Term 2

As CBSE Term 2 exam is been conducted these days and students must have been worrying about the upcoming exam with the new exam pattern as announced by CBSE for the academic year 2021-22. The CBSE Class 10 Science Term 2 Exam will be of descriptive nature for which the time allotted is 2 hours for 15 questions. The paper will be divided into 3 sections-

1. Section–A has 7 questions with 2 marks each

2. Section–B has 6 questions with 3 marks each

3. Section–C has 2 case-based questions of 4 marks each

## CBSE Class 10 Term 2 Answer Key Science

Term 2 Maths Answer Key for both Basic & Standard Mathematics Examination has been discussed in this article after the conduction of Maths Term 2 Exam on 05th May 2022.

## Class 10 Science Term 2 Question Paper & Solution

The students can refer to the CBSE Class 10 Answer Key Science which will be discussed by our expert faculty after the completion of the Term 2 Science Exam on 10th May 2022. To get the accurate and detailed Science Class 10 Term 2 Answer Key 2022, bookmark this page as we will be providing all questions with their correct answers here.

### Class 10 Science Term 2 Question Paper & Solution [31/1/2]

SECTION A

Question 1- (a) What is Ozone? How is it formed in the upper layers of the Earth's atmosphere? How does ozone affect our environment?

Solution- Ozone is the O3 gas formed by the fusion of Oxygen and Nascent Oxygen. When UV radiation act on Oxygen, then 2 oxygen molecule breaks and these molecules join nascent oxygen and forms O3. Any breakdown in the Ozone layer will cause damage to the ecosystem because UV radiation enters the ecosystem causing skin diseases, asthma and other diseases.

OR

(b) (i) List two human-made ecosystems.

Solution- Cropland, Aquarium, Garden

(ii) “We do not clean a pond in the same manner as we do in an aquarium.” Give a reason to justify this statement.

Solution- Ponds and lakes are natural ecosystems and they contain decomposers. Decomposers act as cleansing agents here, whereas an aquarium is an artificial ecosystem, it does not contain decomposers that cleanse it.

Question 2- (a) (i) Name and state the rule to determine the direction of force experienced by a current-carrying straight conductor placed in a uniform magnetic field which is perpendicular to it.

Solution- Fleming's Left Hand Rule. It states that if we arrange our thumb, forefinger and middle finger of the left-hand perpendicular to each other, then the thumb points towards the direction of the magnetic force, and the forefinger points towards the direction of the magnetic field and the middle finger points towards the direction of the current.

(ii) An alpha particle while passing through a magnetic field gets projected towards the north. In which direction will an electron project when it passes through the same magnetic field?

Solution- Force is given by F=qvb

where F= Force, q= Charge, v = velocity, and B is the magnetic field.

Here the alpha particle projected towards the north i.e current is towards the north (middle finger). Particle deflects towards east i.e direction of force is towards the east (thumb). So the direction of magnetic field will be in the upward direction (forefinger)

OR

Question 2- (i) What is a solenoid?

Solution- A solenoid is a device comprised of a coil of wire, the housing and a moveable plunger (armature). When an electrical current is introduced, a magnetic field forms around the coil which draws the plunger in. More simply, a solenoid converts electrical energy into mechanical work.

(ii) Draw the pattern of magnetic field lines of the magnetic field produced by a solenoid through which a steady current flows.

Question 3- (a) What is the variation? List two main reasons that may lead to variation in a population.

Solution- Any type of change in the offspring from the parents is called variation.

Reason- Sexual Reproduction: Fusion of 2 gametes, DNA Copy error.

OR

(b) (i) In a cross between violet flowered plants and white-flowered plants, state the characteristics of the plants obtained in the F1 progeny.

Solution- rise to purple-flowered hybrid plants.

(ii) If the plants of F, progeny are self-pollinated, then what would be observed in the plants of F2 progeny?

Solution- VV, Vv, Vv (3:1) 3 violets, 1 white

(iii) If 100 plants are produced in F, progeny, then how many plants will show the recessive trait?

Solution- 75% Violet (recessive)

Question 4 (a) Which of the following flowers will have a higher possibility of self-pollination?

Mustard, Papaya, Watermelon, Hibiscus

Solution- Hibiscus

(b) List the two reproductive parts of a bisexual flower.

Solution- The two reproductive parts of the bisexual flowers are: Stamen (male part) and pistil (female part).

Question 5 (a) Name the process shown below and define it

Solution- Regeneration- The mode of asexual reproduction, in this is the broken part of the body fully grown by regeneration.

(b) Name the types of cells present in the organisms which exhibit this process.

Solution- Regenerative cells

Question 6- What is a Döbereiner triad ? Why can't the following three elements form such a triad?

N (14); P (31); As (75)

(Atomic masses are given in parenthesis)

Solution- Dobereiner's triads were groups of elements with similar properties that were identified by the German chemist Johann Wolfgang Dobereiner. He observed that groups of three elements (triads) could be formed in which all the elements shared similar physical and chemical properties.

Döbereiner triad is not applicable to Nitrogen, Phosphorus and Arsenic.

Question 7- The molecular formulae of two alkynes, A and B are CyH2 and C3Hy respectively. (a) Find the values of x and y. (b) Write the names of A and B.

Solution-

SECTION B

Question-8 (a) Name the group of organisms which form in the first trophic level of all food chains. Why are they called so?

Solution- Producer- Photyplantos, Plants, Algae. They are called producers because they produce energy for each trophic level by the process of photosynthesis so that plants/organisms have the ability to perform photosynthesis.

(b) Why are the human beings most adversely affected by bio-magnification?

Solution- Bio-magnification is the process in which non-biodegradable substances or chemical get deposited into the east tropic level, by the increase of trophic level the concentration of chemical increases which damage the organs and life. These chemicals can never be degraded into the environment because we do not have enzymes for this. Humans have the highest bio-magnification as we are placed at the highest trophic level.

(c) State one ill-effect of the absence of decomposers from a natural ecosystem.

Solution- The nutrient recycling will stop.

Question-9 (a) (i) Define Electric Power and write its SI unit.

Solution- Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second

(ii) Two bulbs rated 100 W; 220 V and 60 W; 220 V are connected in parallel to an electric main of 220 V. Find the current drawn by the bulbs from the mains.

Solution- 8/11

OR

(b) (i) State Joule's law of heating. Express it mathematically when an appliance of resistance R is connected to a source of voltage V and the current I flows through the appliance for a time t.

Solution- Joule's law of heating states that, when a current 'i ' passes through a conductor of resistance 'r' for time 't' then the heat developed in the conductor is equal to the product of the square of the current, the resistance and time.

(ii) A 5Ω resistor is connected across a battery of 6 volts. Calculate the energy that dissipates as heat in 10 s.

According to formula V= R I
so, I= V/R where v voltage, i current ,, R resistance..
So, I = 6/5 = 1.2 For energy dissipated

Use R= I*V WHERE I= ∆q/∆t ........ 1.2 = ∆q/∆t........

∆q = 1.2×10. = 12 .....

So, R= ∆q*V/∆t.. 12×6 = 72

Question 10- (a) Calculate the resistance of a metal wire of length 2 m and area of cross-section 1.55 x 10-6 m2. (Resistivity of the metal is 2.8 x 10-8 m)

Solution- 3.61 x 10-2Ω

(b) Why are alloys preferred over pure metals to make the heating elements of electrical heating devices

Solution- Alloys are used in electrical heating devices rather than pure metals because the resistivity of an alloy is more than the resistivity of a pure metal. Moreover alloy does not burn (or oxidize) easily even at higher temperature.

CBSE Class 10 Science Term 2 Question Paper PDF- [31/1/1]

CBSE Class 10 Science Term 2 Question Paper PDF- [31/1/2]

CBSE Class 10 Term 2 Date Sheet 2022

Science Class 10 Answer Key 2021-22: FAQs

Ans. Term 2 Answer Key of Science Class 10 2022 has been provided by Career Power in the above article.

Ans. Science Class 10 Term 2 Exam, there are 2 case based questions for 4 mark each.