Test Yourself For CBSE Class X Board 2024: Solve Class X Science Questions From Previous SQPs

The CBSE class X examination is around the corner. This is surely the time to focus rather than getting panicked. Concentrate on studies, and you will definitely achieve your goal.

At this time, constant revision of what you have studied is a crucial aspect of the study process. The questions below will test your preparedness level, and also give an idea of the kind of questions that may be asked.

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The following questions of Class 10 Science have been taken from past sample questions papers of CBSE so, rest assured about the authenticity. The answers have been provided at the end.

Q1. Study the food chain given below and answer the questions that follow:
(2 marks)

Sample Question Paper 2023-24

a) If the amount of energy available at the third trophic level is 100 joules, then how much energy will be available at the producer level? Justify your answer.

b) Is it possible to have 2 more trophic levels in this food chain just before the fourth trophic level? Justify your answer.

Q2. Which of the following pattern correctly describes the magnetic field around a long straight wire carrying current?
(1 mark)

(a) straight lines perpendicular to the wire.

(b) straight lines parallel to the wire.

(c) radial lines originating from the wire.

(d) concentric circles centred around the wire.

Q3. Why is damage to the ozone layer a cause for concern? What are its causes and what steps are being taken to limit this damage?
(3 marks)

Q4. On adding dilute sulphuric acid to a test tube containing a metal ¡®X¡¯, a colourless gas is produced when a burning match stick is brought near it. Which of the following correctly represents metal ¡®X¡¯?
(1 mark)

a) Sodium

b) Sulphur

c) Copper

d) Silver

Q5. An element with atomic number_____ will form a basic oxide.
(1 mark)

Q6. Unit of electric power may also be expressed as:
(1 mark)

i) volt-ampere

ii) kilowatt-hour

iii) watt-second

iv) joule-second

Q7. Explain the processes of aerobic respiration in mitochondria of a cell and anaerobic respiration in yeast and muscle with the help of word equations.
(3 marks)

Q8. Name the substances other than water, that are reabsorbed during urine formation. What are the two parameters that decide the amount of water that is reabsorbed in the kidney?

(2 marks)

Q9. What is the probability of a girl or a boy being born in a family? Justify your answer.
(3 marks)

Q10. Dil. HCl is added to Zn granules.¡± How will you prove that chemical change has taken place here? Support your response with two arguments.
(2 marks)

ANSWERS:

Ans 1.
a) 10000J because only 10% of energy is available for the next trophic level.
b) No, since the loss of energy at each step is so great that very little usable energy will remain after 4 trophic levels.

Ans 2.
(d) The field consists of concentric circles centred around the wire.

Ans 3.
Damage to the ozone layer is a cause for concern because the ozone layer shields the surface of earth from harmful UV radiations from the sun which cause skin cancer in human beings. Synthetic chemicals like chlorofluorocarbons (CFCs) which are used as refrigerants and in the fire - extinguishers are the main reason for the depletion of the ozone layer. Steps taken to limit this damage - Many developing and developed countries have signed and are obeying the directions of UNEP (United Nations Environment Programme) to freeze or limit the production and usage of CFCs at 1986 levels.

Ans 4.
a) Sodium

Ans 5.
d) 11 (2,8,1)

Ans 6.
i) volt-ampere Power = Voltage x Current.

Ans 7.

CBSE Sample question paper 2019-20

Ans 8.
Glucose, amino acids, salts and a major amount of water are selectively re-absorbed as the urine flows along the tube. The amount of water reabsorbed depends on how much excess water there is in the body, and on how much of dissolved waste there is to be excreted.

Ans 9.
There are 50% chances that a girl may be born and 50% chances that a boy may be born. It can be explained as follows:

Most human chromosomes have a maternal copy and a paternal copy. We have 22 such chromosomes. One pair of chromosomes called sex chromosomes is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes, both called X. (XX)

But men have a mismatched pair of sex chromosomes in which one is normal sized ¨C X chromosome while the other is a short one called Y chromosome. (XY)

A child receives one chromosome from mother which is essentially X chromosome.

A child who inherits an X chromosome from her father will be a girl, and one who inherits a Y chromosome from him will be a boy.

Ans 10.
To prove that chemical change has taken place when Dil. HCl is added to Zn granules, check for the following:

• Bubbles of gas/ Evolution of gas
• Change in colour (Zn - silvery grey to black)
• Change in temperature

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