QUIZ – 2020: INSIGHTS STATIC , 6 May 2021 – Science and Technology

Solution: d)

A ray passing through the principal focus of a concave mirror or a ray which is directed towards the principal focus of a convex mirror, after reflection, will emerge parallel to the principal axis.

So, concave mirrors are commonly used in torches, search-lights and vehicles headlights to get powerful parallel beams of light. They are often used as shaving mirrors to see a larger image of the face. The dentists use concave mirrors to see large images of the teeth of patients.

Large concave mirrors are used to concentrate sunlight to produce heat in solar furnaces.

Solution: c)

Carbohydrates are sugars that come in 2 main forms – simple and complex. This is also referred to as simple sugars and starches.

The difference between a simple and complex carb is in how quickly it is digested and absorbed – as well as it’s chemical structure.

Sugars are found in a variety of natural food sources including fruit, vegetables and milk, and give food a sweet taste. But they also raise blood glucose levels quickly.

Sugars can be categorised as single sugars (monosaccharides), which include glucose, fructose and galactose, or double sugars (disaccharides), which include sucrose (table sugar), lactose and maltose.

Complex carbohydrates, also known as polysaccharides, are starches formed by longer saccharide chains, which means they take longer to break down.

Solution: b)

H9N2 is a subtype of the influenza A virus, which causes human influenza as well as bird flu.

Solution: b)

An electric current always produces a magnetic field. Even weak ion currents that travel along the nerve cells in our body produce magnetic fields.

• When we touch something, our nerves carry an electric impulse to the muscles we need to use. This impulse produces a temporary magnetic field.
• These fields are very weak and are about one-billionth of the earth’s magnetic field. Two main organs in the human body where the magnetic field produced is significant, are the heart and the brain. The magnetic field inside the body forms the basis of obtaining the images of different body parts.
• This is done using a technique called Magnetic Resonance Imaging (MRI). Analysis of these images helps in medical diagnosis.

Solution: d)

Photosynthesis is the process by which plants, some bacteria and some protistans use the energy from sunlight to produce glucose from carbon dioxide and water. This glucose can be converted into pyruvate which releases adenosine triphosphate (ATP) by cellular respiration. Oxygen is also formed.