CBSE Class 10 Board Exam 2021

The CBSE Class 10 Science Marking Program 2021 is available here for free PDF download. The Central Board of Secondary Education (CBSE) has released the marking plan for Class 10 Science Sample Paper 2021. This marking scheme will be helpful to know the suggested answers to all the questions given in the sample paper. With the help of this science marking program, students can learn the correct way to answer any question. Furthermore, the CBSE Marking Scheme also specifies the criteria for which marks will be awarded for different answers when checking the answer sheets of CBSE Class 10 candidates.

Below are some questions from the CBSE Class 10 Science Sample Paper and their answers from the CBSE Class 10 Science Marking Program:

1. List any two observations when ferrous sulfate is heated in a dry test tube?

Answer:

• The initial light green color changes to reddish brown
• Colorless gas is formed
• Gas formation (any two)

Or

1. Identify the products formed during 1 ml. Is hydrochloric acid added to 1 gram of sodium metal?

Answer:

Sodium chloride and hydrogen gas.

2. Write the chemical name and chemical formula of the salt used to remove the permanent hardness of the water.

Answer:

Sodium carbonate dehydrate, Na2CO3.10H2O.

3. Which of the following is not observed in a homologous series? Give a reason for your choice.

a) Change in chemical properties

b) Difference in molecular mass of -CH2 and 14u

c) Quality in physical properties

d) Same working group

Answer:

(A) Change in chemical properties

This does not happen because there is only one working group.

4. Why does the afternoon sun appear white?

Answer:

The light is scattered at least in the afternoon.

5. Both a spherical mirror and a thin spherical lens have a focal length (-) 15 cm. What type of glass and lens are these?

Answer:

Both are concave. Alternative answer to credit: plano-concave lens

Also check out: CBSE Class 10 Science Quiz 2020

6. The image formed by a concave glass appears to be larger than the actual, inverted and object. Where is the material placed?

Answer:

Between the primary focus and the center of the curve.

Or

6. Name the area of ​​a lens through which the ray of light passes without encountering any distortion.

Answer:

Optical Center.

7. In the arrangement shown in the figure, two coils are wound on the inactive roller wire. Initially the key was not inserted into the circuit. The key will then be inserted and removed after a while.

What are the two observations that can be observed from the calorimeter reading?

Answer:

There are temporary galvanometer deviations, which die quickly; Deviations are in opposite directions.

8. Draw magnetic field lines around a conductor carrying a direct current.

Answer:

The field consists of concentric circles centered on the wire.

Download the complete marking scheme with CBSE Mathematical Sample Paper from the following links:

Check more: CBSE Class 10 Science Complete Study Material and Board Exam Guide for Preparing 2021