How Things Work
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
How Things Work
SubtopicHow Things Work under How Things Work for Grade 4 CBSE.
Preview questions (no answers)
- 1.
What happens to the friction if we make a surface very smooth?
A.Friction increases
B.Friction decreases
C.Friction remains same
D.Friction becomes gravity
- 2.
Which of these is an example of a second-class lever where the load is in the middle (like a wheelbarrow)?
A.Scissors
B.See-saw
C.Nutcracker
D.Fishing rod
- 3.
Magnetic force can pass through which of the following?
A.A thick iron plate
B.A thin sheet of paper
C.A lead block
D.A steel wall
- 4.
Which of the following requires electrical energy to work?
A.A bicycle
B.A television
C.A wooden boat
D.A hand fan
- 5.
A ramp is a simple machine called an inclined plane. According to the principles of science, how does using a ramp make the work of moving a heavy crate to a higher floor easier compared to lifting it straight up?
A.The ramp reduces the actual weight and mass of the crate.
B.The ramp allows the crate to be moved with less force over a longer distance.
C.The ramp makes the actual distance to the top shorter than a vertical lift.
D.The ramp uses magnetic force to help pull the crate upward automatically.
- 6.
Fossil fuels like coal and petroleum store which type of energy?
A.Solar energy
B.Chemical energy
C.Electrical energy
D.Mechanical energy
- 7.
Which part of a pair of scissors acts as the fulcrum?
A.The handles
B.The sharp edges
C.The screw/joint in the middle
D.The paper being cut
- 8.
A farmer uses a solar-powered irrigation system to water his crops. The flowchart below shows how energy moves through the different components of the system. At which labeled component is electrical energy converted into kinetic energy (the energy of motion)?
A.Solar Panel
B.Connecting Wires
C.Electric Motor
D.Water Pump
- 9.
Which of these would be the most effective way to reduce friction in the moving parts of a bicycle?
A.Washing it with water.
B.Applying grease or oil to the chain.
C.Painting the frame with bright colors.
D.Tightening all the screws as much as possible.
- 10.
Why do astronauts float in space stations orbiting the Earth?
A.There is no gravity at all in space.
B.The space station is moving so fast that it is in a constant state of free-fall.
C.The astronauts have special magnetic boots.
D.There is no air to push them down.
Download the worksheet for How Things Work - How Things Work to practice offline. It includes additional chapter-level practice questions.