IDL 2023 Backup

What is the significance of 16 May, the day set for IDL by UNESCO?

• It is the anniversary for the first successful operation of the laser.

• It is the anniversary for the discovery of photoelectric effect.

• It is Albert Einstein's birthday.

• It is Thomas Edison's birthday.

Answer explanation

The International Day of Light will be held on May 16th every year, the anniversary of the first successful operation of the laser in 1960 by physicist and engineer, Theodore Maiman.

The laser is a perfect example of how a scientific discovery can yield revolutionary benefits to society in communications, healthcare and many other fields.

 

Why is IDL celebrated? 

• To celebrate the creation of light

• To celebrate the birth of Theodore Maiman

• To strengthen camaraderie between scientists

• To strengthen scientific cooperation to foster peace and sustainable development.

Answer explanation

The International Day of Light is a global initiative that provides an annual focal point for the continued appreciation of light and the role it plays in science, culture and art, education, and sustainable development, and in fields as diverse as medicine, communications, and energy.

The broad theme of light will allow many different sectors of society worldwide to participate in activities that demonstrates how science, technology, art and culture can help achieve the goals of UNESCO – education, equality, and peace.

What is astigmatism? 

• The corneas causes light to focus on more than one point at the retina.

• The shape of the eyes cause light to focus in front of the retina, making far-away objects blurry.

• The shape of the eyes make light focus behind the retina, causing nearby objects to look blurry.

• There are cloudy areas in the lenses in the eyes, obstructing light and vision.

Answer explanation

Astigmatism is a condition where the cornea has an imperfect curvature, causing a distortion in vision. A normal cornea is shaped like a sphere but in astigmatism the cornea is oval-shaped, causing problems in focusing the light entering the eye.

What is the word 'laser' an acronym for?

• light artificed by serious explosion of radiation

• light amplification by stimulated emission of radiation

• light abstracted from salvaging and extraction of radiation

• light augmentation by simultaneous expansion of radiation

Answer explanation

Visit the YouTube links below to watch how lasers are produced!

https://www.youtube.com/watch?v=y3SBSbsdiYg

https://www.youtube.com/watch?v=lW4Uq_2VPhE

What is the speed of visible light in a vacuum?

• 330 m/s

• 330 km/h

Answer explanation

The speed of light in a vacuum is defined as exactly 299,792,458 metres per second.

This relationship is used to define the metre as exactly the distance that light travels in vacuum in 1⁄299792458 of a second.

Who is often credited as the inventor of the light bulb?

• Humphrey Davy

• Joseph Swan

• Nikola Tesla

• Thomas Edison

Answer explanation

Though Thomas Edison is usually credited as the man who invented the lightbulb,

Alessandro Volta, Humphrey Davy and Joseph Swan played a critical role in the development of this technology. 

Davy showed that when electric current flowed through wires, their resistance caused them to heat up to the point where they gave out light. Swan publicly demonstrated the first light based on commercially-viable carbon.

Which of the following is the correct sequence for the colours in the visible light spectrum?

• Violet, Indigo, Blue, Green, Yellow, Orange, Red

• Violet, Blue, Indigo, Yellow, Green, Orange, Red

• Violet, Indigo, Green, Blue, Orange, Yellow, Red

• Violet, Blue, Indigo, Green, Orange, Yellow, Red

Answer explanation

Most people would remember the colours in this order: Red, Orange, Yellow, Green, Blue, Indigo, Violet.

Which of the following is an application of visible light?

• X-rays

• Induction heating

• Fiber optics

• Echolocation

Answer explanation

Both x-rays and visible light are part of the electromagnetic spectrum, with different wavelengths and different frequencies.

Echolocation involves the use of reflected soundwaves to determine the position of surrounding objects.

Induction heating uses alternating magnetic fields to induce currents in cookware, generating heat to cook food in the cookware.

Fibre optics involves the use of light in fibre wires to transmit signals.

Which of the following is false about LED lights, as compared to fluorescent and incandescent bulbs?

• They are more eco-friendly.

• They have a longer life span.

• They are cheaper to manufacture and produce.

• They require less power for the same level of brightness.

Answer explanation

LED lights require less power to use, and waste less energy. They do not contain mercury and other hazardous materials, making them more eco-friendly. They also last longer as they do not burn out like traditional light bulbs.

However, manufacturing them is a delicate, complex and expensive process involving the use of semiconductors.

Which of the following colours of light does chlorophyll absorb the least during photosynthesis?

• Blue

• Green

• Orange

• Violet

Answer explanation

Chlorophyll absorbs mainly red, orange, blue and violet colours. They absorb green light the least.