CBSE Extra Questions For Class 8 Science

CBSE Class 8 Science Extra Questions

You must solve Extra Questions for Class 8 Science to understand how much clarity you have on the topics covered in Class 8 Science. You can refer to some Extra Questions for class 8 science with answers or solve them and use formulas on your own to know the learning ability. The given extra questions in class 8 science can help you understand if you need to learn more about the topics or is there any scope for further revision required.

Importance of CBSE Extra Questions for 8 Science

You can study for the final examination with different sources like NCERT books, CBSE revision notes, and CBSE sample papers. The CBSE past year question papers and extra questions of science class 8 can be helpful for students who struggle to learn complex concepts of science. Refer to these CBSE extra questions for class 8 science and cover your CBSE syllabus study materials

Chapter 1 – Crop Production and Management

  1. What is the process of loosening the soil called?

 (a) tilling

(b) harvesting

(c) spraying

(d) weeding

Ans. (a)Tilling

  1. Which is a pesticide from the following?

 (a) 2, 4-dichlorophenoxyacetic acid

(b) Malathion

(c) Metolachlor

(d) Chloroform

Ans.(a) 2, 4-dichlorophenoxyacetic acid

Chapter 2 – Microorganisms: Friend and Foe

  1. Where are the ovum or the eggs formed?

 (a) testes

(b) penis

(c) ovary

(d) evident

Ans. (c)  Ovary

  1. Where do the sperm and the ova fusion usually take place?

 (a) uterus

(b) testes

(c) ovary

(d) oviduct

Ans.(d) Oviduct

Chapter 3 – Synthetic Fibres and Plastics

  1. Name a natural fibre from the following:

 (a) Nylon

(b) Polyester

(c) Rayon

(d) Cotton

Ans.(d) Cotton

  1. Which of these items given below cannot be recycled?

 (a) Cooker handles

(b) Carry bags

(c) Toys

(d) Plastic chair

Ans.(a) Cooker handles

Chapter 4 – Materials: Metals and Non-Metals

  1. Which of the following is the most reactive metal?

 (a) calcium

(b) potassium

(c) silver

(d) copper

Ans.(b) Potassium

  1. Which metal is liquid at room temperature?

 (a) bromine

(b) calcium

(c) mercury

(d) sodium

Ans. (c) Mercury

Chapter 5 – Coal and Petroleum

  1. From the given statements, choose the incorrect one.

 (a) Petroleum gas in liquid form (LPG) is used as fuel in homes and industries

(b) Kerosene is used as fuel for stoves, lamps and jet aircraft

(c) Diesel is used as fuel for heavy motor vehicles, electric generators

(d) Paraffin is used in paints and road surfacing

Ans. (b)Kerosene is used as fuel for stoves, lamps and jet aircraft.

  1. Naphthalene obtained from coal tar is used as a _______

(a) Honey bee repellent

(b) Mosquito repellant

(c) Snake repellant

(d) Moth repellent

Ans. (d)Moth repellent

Chapter 6 – Combustion and Flame

  1. Which of the following is a fuel?

 (a) Solid, liquid or gas

(b) Gas only

(c) Liquid only

(d) Solid only

Ans. (a)Solid, liquid or gas

  1. What type of reaction is combustion?

(a) exothermic

(b) endothermic

(c) volatile

(d) none of these

Ans. (a)Exothermic

  1. Large scale cutting down of trees could result in ___

(a) afforestation

(b) deforestation

(c) both afforestation and deforestation

(d) reforestation

Ans. (b)Deforestation

Chapter 7 – Conservation of Plants and Animals

  1. What are two examples of national parks?

Ans. Dudhwa National Park and Kaziranga National Park.

      2. Explain desertification.

Ans. The conversion of fertile land into desert is called desertification.

      3. What is a Red Data Book?

Ans. A Red Data Book keeps records of all the endangered animal and plant species.

Chapter 8 – Cell – Structure and Functions

  1. The nucleus is separated from the cytoplasm by_____

 (a) cell membrane

(b) nuclear membrane

(c) organs

(d) nucleoplasm

Ans.(b) Nuclear membrane

  1. What do tissues combine to form?

 (a) nucleus

(b) cells

(c) organism

(d) organs

Ans. (d)Organs

  1. Where are chromosomes found?

 (a) nucleus

(b) nucleoplast

(c) nucleolus

(d) vacuole

Ans.(a) Nucleus

Chapter 9 – Reproduction in Animals

  1. Where are the ovum or the eggs formed?

(a) testes

(b) penis

(c) ovary

(d) evident

Ans. (c )Ovary 

  1. Where does the sperm and the ova fusion usually take place?

 (a) uterus

(b) testes

(c) ovary

(d) oviduct

Ans. (d)Oviduct

Chapter 10 – Reaching The Age of Adolescence

  1. Which among the following is the adolescence period?

(a) 14 – 20 years

(b) 10 – 18 years

(c) 11 – 19 years

(d) None of the above

Ans. (c) 11-19 years

  1. Pancreas are responsible for maintaining__________

 (a) blood pressure

(b) fat metabolism

(c) blood glucose level

(d) electrolyte balance

Ans.(c) Blood glucose level

  1. What is Larynx called?

(a) Soundbox

(b) Voicebox

(c) Black box

(d) All the above

Ans.(a) Soundbox

Chapter 11 – Force and Pressure

  1. What is the force exerted by the Earth to pull the object towards itself known as?

(a) gravitational force

(b) electrostatic force

(c) muscular force

(d) contact force

Ans.(a) Gravitational force

  1. Two objects repel each other. Which among the following is the cause of this repulsion?

(a) electrostatic force only

(b) frictional force only

(c) magnetic force only

(d) either a magnetic or an electrostatic force

Ans. (d)Either a magnetic or an electrostatic force

  1. What is a push or pull on an object called?

(a) Pressure

(b) Push-pull

(c) Force

(d) All the above

Ans.(c) Force

Chapter 12 – Friction

  1. ____ produces the least friction.

(a) Rolling friction

(b) Sliding friction

(c) Composite friction

(d) Static friction

Ans.(a) Rolling friction

  1. ______ is responsible for wearing out of bicycle tyres.

(a) Magnetic force

(b) Muscular force

(c) Frictional force

(d) Electrostatic force

Ans.(c) Frictional force

  1. Force of friction is dependent on____

(a) roughness of surface

(b) smoothness of surface

(c) inclination of surface

(d) all of these

Ans. (d)All of these.

Chapter 13 – Sound

  1. What are the differences between ultrasonic sound and infrasonic sound?

Ans. Ultrasonic Sound – The sound that has a frequency more than 20,000 Hz is called ultrasonic sound. Dog, bat, monkey, deer, and many more animals can hear ultrasonic sound.

Infrasonic Sound – The sound that has a frequency lower than 20 Hz is called infrasonic sound. Elephant, whale, giraffe, and hippopotamus can hear this sound.

  1. What is frequency?

Ans. The number of oscillations per second is called frequency. The unit of frequency is Hertz.

  1. What is 1 hertz equal to?

(a)10 vibrations per minute

(b) 1 vibration per minute

(c) 600 vibrations per minute

(d) 60 vibrations per minute

Ans. 60 vibrations per minute

Chapter 14 – Chemical Effects of Electric Current

  1. Name the three effects of electric current.

Answer: Electric current has heating, magnetic and chemical effect.

  1. What is Pure or distilled water? 

(a) good conductor

(b) poor conductor

(c) both (a) and (b)

(d) none of the above

Ans. Poor conductor

  1. You can electroplate Iron objects with____ to protect them. 

(a) chromium

(b) zinc

(c) nickel

(d) all of these

Ans. (d)All of these

Chapter 15 – Some Natural Phenomena

  1. On which scale is the power of an earthquake expressed?

(a) Seismic scale

(b) Iron scale

(c) Richter scale

(d) Large scale

Ans. (c) Richter scale

2.______ takes place during lightning.

(a) Acid rain

(b) Nitrogen fixation

(c) Greenhouse effect

(d) Earthing

Ans. (b)Nitrogen Fixation

Chapter 16 – Light

  1. The Band of seven colours is ______


(b) spectrum

(c) dispersion

(d) reflection

Ans. (b) Spectrum

  1. ______ is not a source of light.

(a) The sun

(b) The moon

(c) Firefly

(d) Tubelight

Ans. Moon

Chapter 17 – Stars and The Solar System

  1. Name the star that is nearest to the Earth.

 (a) Pole star

(c) Sun

(b) Cassiopeia

(d) Orion

Ans. Sun

  1. What is our Galaxy known as?

(a) Sun galaxy

(b) Earth galaxy

(c) Milky Way

(d) Constellation

Ans. Milky Way

Chapter 18 – Pollution of Air and Water

  1. Which of the following is used to purify the high salt concentration in water?

(a) boiling

(b) UV radiation

(c) filtration

(d) reverse osmosis

Ans.(d) Reverse osmosis

  1. _____ results in pollution of water.

(a) oil refineries

(b) paper factories

(c) sugar mills

(d)All of these

Ans. All of these