Mock Test-4 (Paper-1) (Question 51-100)

Retina of the eye is comparable to the film of a traditional camera. Retina is a film of nerve fibres. Image of the object is formed at retina just like camera film is used to see the images.
About Human Eye

• The human eye is a remarkable organ responsible for vision, one of the five primary senses.
• Its structure is designed to capture light and convert it into electrical signals, enabling the brain to perceive images.
• The eye’s outer layer includes the transparent cornea, which helps focus incoming light. Behind the cornea lies the iris, which controls the size of the pupil, regulating the amount of light entering the eye.
• The crystalline lens further adjusts focus, projecting light onto the retina at the back of the eye.
• The retina is lined with photoreceptor cells, rods, and cones, responsible for detecting light intensity and color.
• These signals are transmitted via the optic nerve to the brain’s visual cortex, where they are processed into coherent images.
• Protected by eyelids and lubricated by tears, the eye’s intricate design allows for depth perception, color differentiation, and sharp vision, making it vital for daily activities and interactions.

The cure for nearsighted eye is to equip it with a diverging or concave lens. Since the nature of the problem of nearsightedness is that the light before it reaches the eye. This light will then be converged by the cornea and lens to produce an image on the retina.

Microwave oven consumes less power due to short wavelength of radiation.

microwave oven works by generating high-frequency electromagnetic waves called microwaves. These waves cause water molecules in the food to vibrate rapidly, producing friction that heats the food. This is why foods with higher water content heat faster. The microwaves do not directly heat the vessels or oven cavity.

Modern microwave ovens have built-in safety features like auto shut-off and door interlocks that cut power when the door is opened. This prevents harmful microwave leakage. The inside of the oven is coated with reflective material that does not allow microwaves to escape.

Compared to conventional ovens that can take over an hour to cook meals, microwave ovens use up to 80% less energy to cook food in a fraction of the time. They directly heat the food instead of heating the cavity or vessels first, reducing power consumption. Their smaller size also translates to lower electricity bills. Microwaving leftovers instead of reheating in a conventional oven can lead to significant energy savings over time.

Hypermetropia is a vision condition where nearby objects appear blurry, while distant objects are seen clearly. This occurs because the light entering the eye focuses behind the retina. This can happen if the eyeball is too short or the cornea is not curved enough.

• Difficulty seeing nearby objects clearly.
• Can see distant objects clearly.
• Light focuses behind the retina.
• Corrected using a convex lens, which converges light before it enters the eye, shifting the focus forward onto the retina.

The minimum height of a plane mirror to see the full size image of a person is equal to the half the height of the person.

Mercury exists in liquid state at room temperature. Bromine (Br) also exists as liquid at room temperature however it is a non-metal. Some other metals like caesium, gallium and rubidium exists as liquid slightly above room temperature.

Chlorophyll is a green pigment in which at the centre of the ring is a magnesium ion. It also bears a long phytol chain.

• Chlorophylls, like heme groups, are porphyrins mostly found in plants. As such, they are tetrapyrroles with a metal ion at their center. Unlike heme groups, which contain iron at their center, chlorophyll contains magnesium as its metal ion.
• The pigment’s biosynthesis begins with two key intermediates (uroporphyrinogen Ill and protoporphyrin IX), followed by the insertion of magnesium ion at its core. However, further alterations result in the pigment’s varied shapes and specialisation in different creatures.
• Chlorophyll is made up of the following chemical components: A porphyrin (tetrapyrrole) nucleus containing a chelated magnesium atom — The porphyrin head of the structure is made up of four pyrrole rings with nitrogen grouped in a ring.
• Hydrocarbon chains connected by a carboxylic acid group — The tail component of the structure is made up of a long hydrocarbon chain. Chlorophyll pigments are held in place by proteins that bind to them. This puts them in the proper alignment to capture and transfer light energy during photosynthesis.
• Chelate — An organic molecule containing a metal ion at its center.

Compound Present in Bones - Calcium Phosphate

Acid Present in Vinegar - Acetic Acid

Souring of milk - Lactic acid

Ripening of fruits Ethylene

At room temperature (30°C), Hg, Ga, Cs metals are liquids.

• Liquid metalis a liquid-state metallic material with a low melting point at or around room temperature.
• Owing to their high thermal or electrical conductivity, low viscosity and superior fluidity, liquid metals are emerging as a highly desirable candidate in a broad array of areas, such as flexible electronics, thermal management, soft machines and biomedical materials.
• However, bulk liquid metal is not readily utilized because of its high surface tension and large dimension-induced dexterity limitations.
• To address this challenge, liquid metals have been innovated with micro/nanotechnology to endow the bulk liquid metals with remarkably diversified performances.
• These new functional materials not only possess the softness of classical liquid metals but also have many outstanding properties, including great thermal conductivity, self-healing ability and stimuli-responsive deformability.
• Compared to rigid inorganic micro/nanoscale materials, soft liquid metal micro/nanoparticles demonstrate their unconventionally superior flexibility, compliance and tunability.

Gold is a stable noble metal and resists the action of the atmosphere and occurs in free state.

• Gold is a member of the noble metal family, gold is a beautiful and expensive metal whose name is derived from the Latin aurum, meaning gold.
• It has the atomic symbol ‘Au” and does not interact with other substances or elements. Due to its soft nature, 24 carats in designation and alloys with other metals are pure gold. Only Au-197 isotopes are
  stable.
• It may be discovered naturally in veins and alluvial deposits in the free form and combined with calcite, quartz, silver, lead, zinc, and copper.
• Approximately 1500 pounds of gold are extracted annually. Auric chloride and chloroauric acid are the most prevalent gold derivatives.
• Aqua regia is a solution that combines one component of nitric acid with three parts of hydrochloric acid (because it dissolved gold, the King of Metals). Air and most reagents have little effect on it.