Explanation

Photophobia refers to an extreme sensitivity or fear of light.

It often causing discomfort or pain in the eyes.

Explanation

Isaac Newton proposed the law in 1687

and utilized it to clarify the observed movements of the planets and their moons.

The law of Gravitation had been mathematically formulated by Johannes Kepler in the early 17th century.

ND28-4-2023

Explanation

The key element required for solar energy conversion in most solar cells is silicon

It is the most common semiconductor material: Silicon is used in about 95% of solar cells sold today. 

It is a naturally occurring element: Silicon is the second most abundant element on Earth, after oxygen.

Explanation

• Humans are born with around 300 bones, but as they grow and develop.
• Some of these bones fuse together, resulting in a total of 206 bones in the adult human skeleton.
• This process of bone fusion, called ossification.

Explanation

Benjamin Franklin invented the lightning rod, a device used to protect buildings from lightning strikes.

He made this invention in 1752 as part of his experiments with electricity.

Explanation

Each of these statements is true:

• Water-soluble vitamins cannot be stored in the body: Vitamins like vitamins C and the B vitamins are water-soluble.
• Fat-soluble vitamins can be stored in the body: Vitamins A, D, E, and K are fat-soluble and can be stored in the body's fatty tissues and liver
• The body can absorb more of a fat-soluble vitamin than required: Unlike water-soluble vitamins, excess intake of fat-soluble vitamins can lead to accumulation in the body

Explanation

Neutrons have no electric charge, hence they are neutral.

Protons have a positive charge.

Electrons have a negative charge.

Explanation

An isobar is an imaginary line that connects places of equal barometric pressure.

They can be used to find areas of low or high pressure over a large area.

Explanation

Stainless steel is a alloys that contain a minimum of approximately 11% chromium, a composition that prevents the iron from rusting and also provides heat-resistant properties.

Explanation

A hygrometer measures the amount of water vapor (humidity) in the air.

It is widely used in meteorology, agriculture, and HVAC systems.

Types of hygrometers include mechanical, electronic, and psychrometers.

Maintaining proper humidity is important for health, comfort, and industrial processes.