Explanation

A refracting telescope has two lenses:

1. A primary lens (objective) that collects and focuses light.
2. A secondary lens (eyepiece) that magnifies the focused light to form an image.

Explanation

• Silicon is an example of a Semiconductor.
• Semiconductors like silicon have electrical conductivity between conductors and insulators.
• It enabling them to control electrical current flow in devices and integrated circuits.

Explanation

• The electricity used in homes and schools is typically Alternating Current (AC).
• It is the type of electric current that periodically changes direction.
• This is the type of current provided by power plants and distributed through the grid.

Explanation

• Alternating Current (AC) is the flow of electric charge that periodically changes direction.
• This type of current is commonly used in power distribution systems and household electrical outlets.

Explanation

The renewable energy sources are:

• Water energy
• Wind energy
• Tidal energy
• Hydroelectric
• Ocean energy
• Geothermal energy
• Biomass
• Biogas

The non-renewable energy sources are:

• Fossil fuels or Hydrocarbon fuel (Oil, Natural gas, Coal)
• Nuclear energy

Explanation

• Biomass energy is derived from organic matter such as wood, crops, and waste.
• It is used as a fuel to produce heat energy.
• This heat energy can be used for various purposes, including heating homes, water, and air, as well as powering industrial processes and generating electricity.

Explanation

• When animals and plants decay in the absence of air (anaerobic conditions), they produce a gas called biogas.
• Biogas is a mixture of methane (CH4) and carbon dioxide (CO2), with small amounts of other gases.
• It is produced through anaerobic digestion, a process in which microorganisms break down organic matter without oxygen.

Explanation

• Nuclear energy is a form of energy that is stored in the nucleus of an atom of an element.
• It is the energy that holds the protons and neutrons together in the nucleus.
• It can be released through nuclear reactions such as fission or fusion.

Explanation

• The magnet is the part of a bicycle dynamo that spins to generate electricity.
• When the magnet rotates, it induces an electric current in the coils of the dynamo.
• It producing electricity to power the bike's lights or other accessories.

Explanation

• The flow of electrons is called Electric Current.
• Electric current is the flow of electrons through a conductor, such as a wire.
• It is measured in amperes (A).