Explanation

The "opposing" Electromotive Force is often described as a Back Electromotive Force (Back EMF).

This is the voltage generated in opposition to the applied voltage in a circuit.

This particularly in inductive components like motors or coils, due to changes in current.

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).

Explanation

• The Second is the SI unit of time.
• It is defined as 9,192,631,770 periods of a caesium-133 atom's radiation.

Explanation

• Galileo Galilei is credited with creating his own improved version of the telescope in 1609, based on the design of the "Dutch perspective glasses".
• Although he did not invent the telescope, his improvements to the design and his astronomical discoveries using the telescope made him a key figure in its history.

Explanation

The Earth and the Sun are approximately 25,000 light-years away from the center of the Milky Way galaxy.

Explanation

• Nuclear fusion is the process by which atomic nuclei combine to form a heavier nucleus, releasing vast amounts of energy in the process.
• In the case of stars, nuclear fusion occurs when hydrogen atoms fuse together to form helium, releasing energy in the form of light and heat.

Explanation

• A movable pulley is a type of pulley system where the pulley is free to move along the rope or cable.
• This allows the force applied to the rope to be multiplied, making it easier to lift or move heavy loads.
• Movable pulleys are commonly used in cranes, winches, and other lifting machines.

Explanation

• Electromagnets can be easily turned on and off by controlling the electric current flowing through them.
• It making them useful in applications like cranes (where they can be used to lift and release heavy loads) and doorbells (where they can be used to strike a bell or activate a buzzer).
• This switchability is a key characteristic that makes electromagnets useful in many applications.

Explanation

• In Winter, days become shorter and nights become longer, due to the Earth's axis being tilted away from the Sun.
• Resulting in less direct sunlight reaching the Northern Hemisphere.

Explanation

• At the end of a communication system, such as a radio receiver or a phone, the signal is converted from radio waves (electromagnetic waves) to sound waves, which are perceived as sound by the human ear.
• This conversion is done through a speaker or earphone, which converts the electrical signal into sound waves.