Here are the Class 8 Science Sample Paper for upcoming exam. CBSE sample paper is most important for your exam. You can enjoy the CBSE sample paper for class 8 science 2023-24 with solution.
Class VIII Session 2023-24
Subject – Science
Sample Question Paper – 1
General Instructions:
- The question paper consists of 19 questions and is divided into four sections, A, B and C.
- All questions are compulsory.
- Section A comprises question numbers 1to 7. These are SAQs carrying two marks each.
- Section B comprises question numbers 8 to 16. These are SAQs carrying four marks each.
- Section C comprises question numbers 17 to 19. These are SAQs carrying five marks each.
Table of Contents
Section A
1. What are communicable diseases? Explain with examples.
Answer-: The microbial diseases that can spread from an infected person to a healthy person through air, water, food or physical contact are called communicable diseases. Examples of such diseases include cholera, common cold, chicken pox and tuberculosis.
2. What do you understand by petrochemicals?
Answer-: Those chemicals which are obtained from petroleum and natural gas are called petrochemicals. For example methyl alcohol, ethyl alcohol, formaldehyde, acetone, acetic acid, ethylene, benzene, toluene, vinyl chloride etc.. They are used to manufacture a wide range of products.
3. If you hold a piece of iron wire with a pair of tongs inside a candle flame or a Bunsen burner flame, what will you observe? Will it produce a flame?
Answer-: Iron wire will become red hot and glow. It will not produce a flame.
4. What are the changes seen in girls at the time of puberty?
Answer-: The various changes that occur into girls at the time of puberty are
(a). hair growth in the armpits and pubic region.
(b). development of mammary glands or breasts.
(c). onset of menstruation cycle due to production of eggs or ova by the ovaries.
(d). increased oil secretion in the skin.
5. How does loudness of sound is affected by amplitude?
Answer-: Loudness of sounds is proportional to the square of amplitude of the vibrations producing the sounds. If the amplitude becomes twice, the loudness increases by a factor of four. The unit of loudness is decibel (dB). The sound above 80 dB becomes physically painful. The loudness of sound depends on the amplitude. When the amplitude of vibration is large the sound produced is loud, when the amplitude is small the sound produced is feeble.
6. What is the application of chemical effects of electricity in our daily life? Give examples.
Answer-: Carrying chemical reactions by the effect of electricity is called chemical effect of electric current.
Example of Chemical Effect
(i). Electroplating : One metal is coated on the other substance or metal by the effect of electric current. This is called electroplating.
(ii). Electrolysis : The compound is decomposed into its constituents under the effect of electric current is called electrolysis.
7. Look at the figure. Can the image of the child in it be obtained on a screen?
Answer-: The image of the child cannot be obtained on the screen because the image is not real. The images formed by the plane mirror are virtual, so these virtual images cannot be seen (or obtain) on the screen.
Class 8 Science Sample Paper With Answer
Section B
8. Soil preparation is one of the types of agricultural practices. What do you understand by soil preparation?
Answer-: Soil preparation involves a loosening of the soil or turning it. This process enables the roots to penetrate easily. It aerates the roots by providing the air trapped in between the particles of soil. It also provides favorable conditions for the growth of worms and microorganisms which increase the fertility of the soil.
Some tools used in agricultural practices are given below.
(i). Ploughs are used for tilling the soil, adding manure and fertilizers and for scrapping the soil.
(ii). Leveler is used for levelling the soil in order to prevent it from soil erosion. A plank is used to break the crumbs into fine soil.
(iii). Hoe was used for tilling in olden days, but these days, we use it only to remove weeds. Cultivator pulled by a tractor is also used to break the soil.
9. State difference between coke, coal tar and coal gas?
10. Explain binary fission in amoeba?
Answer-: The type of asexual reproduction in which an animal reproduces by dividing into two individuals is called as the binary fission. It is usually found in single celled organisms such as “AMOEBA”.
(i). It begins the process of reproduction by the division of its body into two nuclei.
(ii). This is followed by division of its body into two each part receiving a nucleus.
(iv). Finally two daughter amoeba are produced from one parent amoeba.
11. Label the missing parts of the endocrine glands.
Answer-: a. Pineal gland
b. Pituitary gland
c. Thyroid
d. Thymus
12. When a person stands on a cushion, the depression is much more than when he lies down on it. Explain with a reason.
Answer-: When a man stands on a cushion then his two feet are in contact with the cushion. Due to this his body weight falls on a small area. On the other hand when a man lies on the cushion, his whole body comes in contact with the cushion. His weight falls over the large area because of which the depression in the cushion is less than when he stands on it.
13. How do trees planted along roadside help in the reduction of noise pollution?
Answer-: Trees have the ability of absorbing sound and not letting it escape and also by reflecting the sound among the trees it lessens the speed of the sound so the impact is generally low. That is why it is advisable to plant trees alongside the roads and around buildings so that it cut down the sound.
14. What do you mean by electroplating? How does it take place?
Answer-: The process of coating a desired metal on other metal surface by using electric current is called electroplating.
(i). A metal plate and the substance to be coated are dipped in a current conducting solution with conducting wires.
(ii). The object to be coated is attached to the negative terminal.
(iii). When electric current is passed through the solution, the compounds of the conducting solution start breaking.
(iv). The free metallic particles get deposited on the object at negative terminal of the battery.
In this way we can get a coating of desired metal on any object by preparing suitable conducting solution and by using suitable electrodes.
15. What is lightning. Explain the experiment conducted by Benjamin Franklin that showed sparks shared some similarity with lightning?
Answer-: Lightning is an atmospheric discharge of electricity, which typically occurs during thunderstorms and sometimes during volcanic eruptions or dust storms. In June 1752, Benjamin Franklin raised a kite, accompanied by his son Williams as an assistant. On his end of the string he attached a key, and he tied it to a post with a silk thread.
After some time he noticed that small pieces of string began to stand apart like the hair on the back of a scared dog. He then brought his hand close to the key and received a tingle of an electric shock from the key. As the rain came down, the string became soaked and the electricity began to conduct freely through the key.
16. Name the following:
i. The layer of tissue that protects light sensitive inner parts of the eye and prevents internal reflection of light
ii. Tough opaque sheet of tissues that forms the outer covering of the eye
iii. The transparent, watery fluid found in between the cornea and the lens
iv. The spot on the retina where an object forms the sharpest image.
Answer-: i. choroid
ii. Selera
iii. Aqueous humor
iv. Yellow spot
Online Test For Class 8 Science Sample Paper
(Section D)
(i) Name the process in which tadpoles develop into young frogs.
a) Fertilization
b) Embedding
c) Budding
d) Metamorphosis
Answer-: (d) Metamorphosis
Explanation: Metamorphosis
(ii) The process by which organisms make copies of themselves is called .
a) reproduction
b) transpiration
c) Photosynthesis
d) respiration
Answer-: (a) reproduction
Explanation: reproduction
(iii) Which of the following is an example of a viviparous animal?
a) Cat
b) Fish
c) Hen
d) Cobra
Answer-: (a) Cat
Explanation: Cat
(iv) In human beings, body parts_________ to those present in the adults are present from the time of birth.
Answer-: similar
(v) Tadpoles, transform into adults capable of jumping and swimming.
a) True
b) False
Answer-: (a) True
Explanation: True
Answer-: (d) Opposite
Explanation: Opposite
(ii) Which of the following is example of frictional force?
a) All of these
b) we stop paddling a bicycle; it gradually slows down and finally comes to a stop.
c) A car or a scooter also comes to rest once its engine is switched off.
d) Boat comes to rest if we stop rowing it.
Answer-: (a) All of these
Explanation: All of these
(iii). The force exerted by our muscle is called
a) electrostatic force
b) gravitational force
c) non-contact force
d) muscular force
Answer-: (d) muscular force
Explanation: muscular force
(iv). When we push an object like a school bag or lift a bucket of water_______force is applied.
Answer-: muscular
(v). Animals also make use of muscular force to carry out their physical activities and other tasks.
a) True
b) False
Answer-: (a) True
Explanation: True
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Read the text carefully and answer the questions:
Neha is teaching her friend about electroplating she told that brand new bicycle has shiny handlebar and wheel rims. However, if these are accidentally scratched, the shiny coating comes off revealing a not so shiny surface beneath. The women using ornaments, which appear to be made of gold. However, with repeated use, the gold coating wears off, revealing silver or some other metal beneath. In both these cases, a metal has a coating of another metal.
(i) The Electroplating is based on
a) chemical effect of electricity
b) heating effect of electricity
c) physical effect of electricity
d) magnetic effect of electricity
Answer-: (a) chemical effect of electricity
Explanation: chemical effect of electricity
(ii) Waste from an electroplating factory must be disposed off
a) in the nearby cornfield
b) in the nearby pond
c) in the nearby river
d) according to the disposal guidelines of Waste Management Bodies
Answer-: (d) according to the disposal guidelines of Waste Management Bodies
Explanation: according to the disposal guidelines of Waste Management Bodies
(iii) Electroplating prevents
a) passing of current
b) shining
c) corrosion
d) dissociation
Answer-: (c) corrosion
Explanation: corrosion
(iv) Chromium has a_______ appearance.
Answer-: Shiny
(v) Jewelry makers electroplate silver and gold on expensive metals.
a) True
b) False
Answer-: (b) False
Explanation: False