CBSE Class 4 EVS Work Force And Energy Worksheet

I. FILL IN THE BLANKS

Question 1. The __________ is used to rotate the blades of a windmill and also helps the ships to move in the sea.
Answer: wind
In simple words: Moving air is called wind, which has the power to turn windmill blades and push sailing ships.

Exam Tip: Remember that wind is a source of renewable energy.

Question 2. Our __________ is an example of force inside our body.
Answer: muscles (or muscular force)
In simple words: The force exerted by our body muscles is called muscular force.

Exam Tip: Muscular force is required for all physical movements like walking, lifting, and running.

Question 3. An __________ is a smallest and invisible particle of matter.
Answer: atom
In simple words: Atoms are the tiny building blocks that make up all matter in the universe.

Exam Tip: Atoms are so small that they cannot be seen with the naked eye.

Question 4. Burning of fuels produces __________.
Answer: heat energy (and light energy)
In simple words: When fuels burn, they release stored chemical energy in the form of heat.

Exam Tip: Mention both heat and light when asked about burning fuels.

Question 5. All movements are the result of some kind of __________ applied on that object.
Answer: force
In simple words: Force is a push or pull that causes objects to move, stop, or change shape.

Exam Tip: Force can never be seen, but its effects are visible.

Question 6. Energy present in a hot body is called __________.
Answer: heat energy
In simple words: Objects that are warm or hot possess thermal or heat energy.

Exam Tip: Heat energy flows from hotter bodies to colder bodies.

Question 7. All living things use __________ to work.
Answer: energy
In simple words: Energy is the capacity to do work, and all living organisms get it from food.

Exam Tip: Food is the primary fuel for living beings.

Question 8. Work is said to be done, when there is a __________ in that object.
Answer: movement (or displacement)

In simple words: In science, work only happens when a force moves an object from one place to another.

Exam Tip: Pushing a heavy wall does not constitute scientific work if the wall does not move.

II. SAY TRUE OR FALSE. IF FALSE WRITE THE CORRECT STATEMENT

Question 1. Atom is one of the sources of energy. (      )
Answer: True
In simple words: Nuclear energy is obtained from atoms, making them a powerful source of energy.

Exam Tip: Nuclear power plants generate electricity using atoms.

Question 2. Energy cannot be changed from one form to another. (      )
Answer: False.
Correct statement: Energy can be changed from one form to another.
In simple words: Energy is constantly transformed from one type to another, such as electrical energy converting into light energy in a bulb.

Exam Tip: This principle is known as the conservation and transformation of energy.

Question 3. The magnet attracts iron objects due to mechanical force. (      )
Answer: False.
Correct statement: The magnet attracts iron objects due to magnetic force.
In simple words: Magnets exert a magnetic force, not a mechanical force, on magnetic materials like iron.

Exam Tip: Mechanical force requires direct physical contact or tools, whereas magnetic force acts at a distance.

III. GIVE REASONS:

Question 1. An object thrown upwards after reaching a height returns back towards earth because __________.
Answer: of the gravitational force exerted by the Earth.
In simple words: Earth pulls everything toward its center due to gravity.

Exam Tip: Gravity is a non-contact pulling force.

IV. ANSWER THE FOLLOWING

Question 1. What is hydroelectricity?
Answer: Electricity produced from the energy of flowing or moving water is called hydroelectricity.
In simple words: Water power is harnessed to generate electric current.

Exam Tip: Mention both water and electricity in your definition.

Question 2. How force applied can change a body?
Answer: Force can change a body in the following ways:
1. It can move a stationary object or stop a moving object.
2. It can change the speed or direction of a moving object.
3. It can change the shape and size of an object.
In simple words: Applying force alters the state of motion or physical appearance of an object.

Question 3. Write the uses of windmill?
Answer: The main uses of a windmill are:
1. Generating electricity.
2. Drawing water from underground wells.
3. Crushing grains into flour.
In simple words: Windmills use wind power to perform mechanical and electrical work.

Exam Tip: Electricity generation is the most common modern use of windmills.

V. WRITE THE FORMS OF ENERGY USED IN THE FOLLOWING EXAMPLES:

Question 1. Horses pulling a cart -
Answer: Muscular force / Muscular energy
In simple words: Animals use their muscles to pull loads.

Exam Tip: Muscular energy comes from the food animals eat.

Question 2. During photosynthesis on leaves -
Answer: Solar energy / Light energy
In simple words: Plants trap sunlight to make their food.

Exam Tip: Solar energy is essential for plant life.

Question 3. Television -
Answer: Electrical energy (which changes into light and sound energy)
In simple words: TVs run on electricity.

Exam Tip: Electrical appliances convert electrical energy into other useful forms.

Question 4. Rotation of windmill's blades -
Answer: Wind energy
In simple words: Moving air turns the blades.

Exam Tip: Wind energy is clean and inexhaustible.

VI. MATCH THE FOLLOWING:

Question 1. Match the items correctly:
1. Moving air - wind (5)
2. Stretching a rubber band - elastic force (1)
3. Solar heater - heating water (4)
4. Mechanical force - tools are used (3)
5. No movement - work is not done (2)
Answer: 1 - wind, 2 - elastic force, 3 - heating water, 4 - tools are used, 5 - work is not done
In simple words: Each concept is paired with its correct definition or application.

Exam Tip: Draw clear lines or write matching numbers next to the options.

VII. NAME THE FOLLOWING:

Question 1. Name the energy obtained from electricity.
Answer: Electrical energy
In simple words: Energy derived from electric charge is electrical energy.

Question 2. Name the electricity produced from flowing water or moving water.
Answer: Hydroelectricity
In simple words: Water flow turns turbines to make electricity.

Exam Tip: 'Hydro' means water.

Question 3. Name the force applied with the help of tools.
Answer: Mechanical force
In simple words: Tools make our work easier by applying mechanical force.

Exam Tip: Hammers, scissors, and spanners use mechanical force.

Question 4. Name the energy possessed by wind.
Answer: Wind energy
In simple words: The kinetic energy of moving air is wind energy.

Exam Tip: Wind energy is harnessed in windy regions and coastal areas.

Question 5. Name any two fuels used in automobiles.
Answer: Petrol and Diesel (or CNG)
In simple words: Vehicles run on liquid or gas fuels.

Question 6. Name the energy stored in muscles of humanbeings and animals.
Answer: Muscular energy
In simple words: Chemical energy from food converts into muscular energy in living bodies.

Exam Tip: Muscular energy enables physical exertion.

Question 7. Name any two fuels used for cooking purposes in olden days.
Answer: Wood and Dried dung cakes (or Coal)
In simple words: Traditional fuels used before LPG became common.

Exam Tip: Wood and coal produce smoke when burned.

LESSON NO: 6 SENSE ORGANS

I. FILL IN THE BLANKS:

Question 1. The __________ of the object which we see is formed inside the eyes.
Answer: image
In simple words: Light entering our eyes forms images on the retina.

Exam Tip: The eye acts like a natural camera.

Question 2. We should sit atleast __________ away while watching TV.
Answer: 6 feet (or two meters)
In simple words: Sitting too close to a screen strains and damages our eyes.

Exam Tip: Maintain a safe viewing distance from screens to protect vision.

Question 3. Listening to __________ and __________ hurt our ears.
Answer: loud music / noise
In simple words: Excessive loud sounds can damage delicate eardrums.

Exam Tip: Protect your ears from high-decibel sounds.

Question 4. The __________ from sense organs sends and receives messages from the brain.
Answer: nerves
In simple words: Nerves act as communication cables between body parts and the brain.

Exam Tip: Sensory nerves carry messages from sense organs to the brain.

Question 5. The thinnest skin is the skin in our __________.
Answer: eyelids
In simple words: Eyelid skin is extremely thin and delicate.

Question 6. Apply __________ on the scratch or cut on the skin to keep away the germs.
Answer: antiseptic cream / lotion
In simple words: Antiseptics kill germs and prevent infections in wounds.

Exam Tip: Always clean a cut before applying antiseptic ointment.

Question 7. Through __________ we get information about the five senses.
Answer: sense organs
In simple words: Eyes, ears, nose, tongue, and skin are our five sense organs.

Exam Tip: Sense organs connect us to the outside world.

II. MATCH THE FOLLOWING:

Question 1. Match the following:
1. Toughest skin - bottom of our feet (4)
2. Ears - sense of hearing (5)
3. Tongue - sense of taste (2)
4. Soft music - pleasant to hear (3)
5. Eyes - sense of sight (1)
Answer: 1 - bottom of our feet, 2 - sense of hearing, 3 - sense of taste, 4 - pleasant to hear, 5 - sense of sight
In simple words: Match each body part or sensation to its correct description.

Exam Tip: The skin at the soles of our feet is the thickest and toughest.

III. GIVE REASONS

Question 1. We should not clean our eyes and ears with dirty hands and handkerchief.
Answer: Because dirty hands and handkerchiefs carry germs and dust that can cause infections or damage our eyes and ears.
In simple words: Unclean objects transfer harmful bacteria into delicate sense organs.

Exam Tip: Always use clean, soft cloths or tissues for personal hygiene.

IV. CIRCLE THE ODD ONE: WRITE THE REASON

Question 1. Skin      tongue      ears      teeth
Answer: Teeth
Reason: Skin, tongue, and ears are sense organs, whereas teeth are part of the digestive system used for chewing food.
In simple words: Teeth are not counted among the five sense organs.

Exam Tip: Identify the odd one based on biological categorization.

Question 2. Sweet      sour      salty      eyes
Answer: Eyes
Reason: Sweet, sour, and salty are tastes perceived by the tongue, whereas eyes are a sense organ for sight.
In simple words: Taste sensations belong to the tongue, while eyes are visual organs.

Question 1. Name the sense organ of smell.
Answer: Nose
In simple words: The nose detects different odors in the air.

Exam Tip: Olfactory receptors in the nose help us smell.

Question 2. Name the script used for the blind people to read.
Answer: Braille script
In simple words: Braille uses raised dot patterns for tactile reading.

Exam Tip: Invented by Louis Braille.

VI. Answer the following:

Question 1. What are the five senses used by our body?
Answer: The five senses are:
1. Sight (seeing)
2. Hearing (listening)
3. Smell (odor detection)
4. Taste (flavor perception)
5. Touch (feeling texture and temperature)
In simple words: These five senses help us perceive the world around us.

Exam Tip: Associate each sense with its corresponding organ.

Question 2. Why should not we read in a moving bus or train?
Answer: We should not read in a moving vehicle because the constant shaking and changing focus strain our eye muscles, which can damage vision.
In simple words: Bouncy motion makes it hard for eyes to focus steadily on words.

Question 1. Birds build __________ types of nest.
Answer: different (or various)
In simple words: Different bird species construct nests suited to their needs.

Exam Tip: Tailorbirds, weaver birds, and woodpeckers build distinct nests.

Question 2. Birds __________ and __________ their youngones in their nests until they are ready to fly.
Answer: lay eggs / feed (protect)
In simple words: Nests provide a safe nursery for eggs and hatchlings.

Exam Tip: Parent birds care for their chicks until they can fly independently.

Question 3. __________ make their nest on ground by collecting pebbles and bones.
Answer: Penguins
In simple words: Penguins live in icy regions where twigs are unavailable, so they use pebbles.

Exam Tip: Penguins live in polar regions like Antarctica.

Question 4. __________ burrows a hole on the bank of a river and uses it as its nest.
Answer: Kingfisher
In simple words: Kingfishers dig riverbanks to create safe nesting burrows.

Exam Tip: Water-side birds often nest in burrows.

Question 5. A spider lives in the web it __________.
Answer: spins
In simple words: Spiders secrete silk threads to spin sticky webs for shelter and catching prey.

Exam Tip: Spider webs are made of protein silk.

Question 6. __________ live in underground colonies.
Answer: Ants (or Termites / Bees)
In simple words: Social insects build large underground tunnels and chambers.

Exam Tip: Ants live in organized colonies with a queen.

Question 7. We make shelters for our __________ and __________ animals.
Answer: domestic / pet
In simple words: Humans build sheds, kennels, and stables for animals kept at home or farms.

Exam Tip: Domestic animals depend on humans for shelter.

Question 8. Softbodied animals protect themselves with __________ which they carry on their back.
Answer: shells
In simple words: Hard external shells shield soft-bodied creatures from predators.

Exam Tip: Snails and tortoises hide inside their shells when threatened.

II. CIRCLE THE ODD ONE: WRITE THE REASON BELOW

Question 1. Monkey      squirrel      rabbit      leopard
Answer: Rabbit
Reason: Monkey, squirrel, and leopard are arboreal or tree-dwelling / forest agile animals, whereas rabbits are burrowing land animals that live in burrows.
In simple words: Rabbits live underground in burrows, unlike the others.

Exam Tip: Notice animal habitats when solving odd-one-out questions.

Question 2. Fish      whale      octopus      lion
Answer: Lion
Reason: Fish, whale, and octopus are aquatic animals living in water, whereas a lion is a land animal (terrestrial).
In simple words: Lions live on land, while the others live in water.

Exam Tip: Aquatic vs. Terrestrial classification.

Question 3. Draw the five sense organs
Answer: (Students should draw: Eyes, Ears, Nose, Tongue, and Skin/Hand representation).
In simple words: Sketch the organs corresponding to sight, hearing, smell, taste, and touch.

Exam Tip: Label your sketches clearly.

III. STATE TRUE OR FALSE. IF FALSE WRITE THE CORRECT STATEMENT.

Question 1. Cuckoo builds its own nest. (      )
Answer: False.
Correct statement: Cuckoo does not build its own nest; it lays its eggs in the nests of other birds like crows.
In simple words: Cuckoos are parasitic nesters.

Exam Tip: Cuckoos trick other birds into raising their chicks.

Question 2. A tailor-bird makes its nest by drilling a hole in the trunks. (      )
Answer: False.
Correct statement: A woodpecker makes its nest by drilling a hole in tree trunks (or A tailor-bird stitches leaves together to make its nest).
In simple words: Woodpeckers drill wood, while tailorbirds sew leaves.

Exam Tip: Match bird names with their unique nest-building techniques.

Question 3. Nocturnal animals are active and seen during night time (      )
Answer: True
In simple words: Animals that sleep during the day and hunt at night are called nocturnal.

Exam Tip: Owls and bats are examples of nocturnal animals.

IV. NAME THE FOLLOWING:

Question 1. Name any two terrestrial animals.
Answer: Lion and Horse (or Cow, Dog, Elephant)
In simple words: Animals that live predominantly on land.

Exam Tip: Terrestrial means land-dwelling.

Question 2. Name any two arboreal animals.
Answer: Monkey and Squirrel
In simple words: Animals that spend most of their time on trees.

Exam Tip: 'Arbor' refers to trees.

Question 3. Name any two softbodied animals with shells on their back.
Answer: Snail and Tortoise (or Turtle / Oyster)
In simple words: Creatures with soft bodies protected by hard external shells.

Exam Tip: Shells offer protection from harsh weather and predators.

V. ANSWER THE FOLLOWING:

Question 1. Why cuckoo is called as a lazy bird?
Answer: Cuckoo is called a lazy bird because it does not build its own nest; instead, it lays its eggs in the nests of other birds like crows.
In simple words: It relies on other birds to incubate its eggs and feed its young.

Exam Tip: Remember this unique behavioral trait of cuckoos.

Question 2. Why do birds build their nest?
Answer: Birds build nests to lay eggs, hatch them safely, protect their young ones from bad weather (rain, wind, sun), and keep them safe from enemies and predators.
In simple words: Nests provide a safe home and nursery for bird families.

Exam Tip: Mention safety, eggs, and protection from predators.

Question 3. What are the materials used by sparrows and pigeons to build their nests?
Answer: Sparrows and pigeons use twigs, straw, grass, cotton, feathers, and bits of paper or thread to build their nests.
In simple words: They collect dry plant parts and soft fibers to make cozy nests.

Exam Tip: Sparrows often build nests in house corners and ventilation holes.