YEAR 4 SCIENCE CHAPTER 7

What is energy?

• Energy is the number of vibrations in a music system

• Energy is the depth of the water level

• Energy is the ability to do work

• Energy is the ability to focus on something

Is this energy transformation of the bulb is correct?

Electrical energy to Light energy + Heat energy

• Yes

• No

Answer explanation

When light is switched on, the electrical energy will flow through the bulb and heat the filament to produce the light and heat energy

Which is the following below non-renewable energy sources?

• Sun, water and fuel

• Fuel, natural gas and nuclear energy

• Wind and Light

• Coal. water and electrical energy

Answer explanation

Non-renewable energy sources are limited, and their usage should be controlled

Which of the following below are the methods to conserve energy?

• Cut down the trees as they block the roadways

• Use eco-friendly items to save energy

• Switch off the air conditioner if not using it

• Wash clothes in bulk to reduce the washing machine and water usage

We should depend more on non-renewable energy sources in future to protect the environment

• Yes

• No

Answer explanation

Non-renewable energy sources are limited, and they produce harmful products to earth

What are the disadvantages of renewable energy sources?

• Less cost

• Can be in any locations

• Depends on natural sources

• High cost

Answer explanation

Renewable energy sources are highly cost, difficult to find a strategic location without any natural occurrences, and depends on the natural sources (sun, water, wind, heat)

We should use more cars to develop the economy of the country

• No

• Yes

Answer explanation

High number of cars can release huge amount of exhaust gases (from the burning of fuels) that can cause air pollution and increase in temperature

What are the disadvantages of non-renewable energy sources?

• Save cost

• Can use for lifetime

• Produce harmful radiation substances

• Protects the environment

Answer explanation

Nuclear energy uses the radioactive substances (Uranium) that releases harmful radioactive side products

State the transformation of energy that involved when the TV is switched on

• Electrical energy to Kinetic energy + Sound energy

• Chemical energy to Electrical energy

• Potential energy to Light energy +Heat energy

• Electrical energy to Light energy + Sound energy + Heat energy

Answer explanation

When TV is on, the electrical energy will flow into the TV to produce the image (light energy) and the sound of the audio (sound energy)

Why should we use the energy wisely?

• To help to increase the electricity bills

• To have a grand life with high energy usage products

• To save the electrical costs and to preserve the environment

• To release the radioactive substances to the environment