Explanation: Trichology is derived from the Greek word “trikhos”, meaning hair. It is a specialized field within dermatology that focuses on the structure, function, and diseases of hair and scalp. Trichologists diagnose and treat conditions such as hair loss (alopecia), dandruff, scalp infections, and hair shaft disorders.

Common Hair Disorders Studied in Trichology:

• Alopecia: Hair loss due to genetics, stress, or autoimmune disorders.
• Dandruff (Seborrheic dermatitis): Scalp condition causing flaking and itching.
• Tinea capitis: Fungal infection of the scalp (ringworm).

Explanation: A concave lens always forms a virtual, erect, and diminished image, regardless of the position of the object. The image formed appears on the same side of the lens as the object and is used in devices like spectacles for correcting short-sightedness (myopia).

Swine Flu is caused by the H₁N₁ virus, a subtype of the Influenza A virus. It primarily affects the respiratory system and is transmitted from person to person through droplets from coughs or sneezes. Symptoms include fever, cough, sore throat, body aches, and fatigue. The H₁N₁ pandemic in 2009 was declared a global health emergency by the World Health Organization (WHO).

Other options (for context)

• Dengue: Caused by the Dengue virus, transmitted by Aedes mosquitoes.
• AIDS: Caused by the HIV (Human Immunodeficiency Virus), not H₁N₁.
• Bird flu: Caused by the H5N1 virus, not H₁N₁.

An Atom bomb works on the principle of nuclear fission. In this process, the nucleus of a heavy atom such as Uranium-235 or Plutonium-239 splits into two or more smaller nuclei when bombarded with a neutron. This splitting releases a tremendous amount of energy along with more neutrons, which further cause chain reactions — leading to a massive explosion.

Other options (for context)

• Chemical reaction: Produces far less energy; used in conventional explosives, not atomic bombs.
• Nuclear fusion: Powers hydrogen bombs (thermonuclear bombs), not atomic bombs.
• Atomic collision: General term — does not describe the chain reaction mechanism in fission.

Explanation: Mercury is the nearest planet to the Sun. It is the smallest planet in the solar system and completes one revolution around the Sun in just about 88 Earth days. Due to its proximity, Mercury experiences extreme temperature variations between day and night.

Explanation: The primary colours of light are Red, Green, and Blue (RGB). These are the fundamental colours that can be combined in different proportions to produce all other colours in the visible spectrum. Yellow is not a primary colour—it is a secondary colour formed by mixing red and green light. This principle of colour mixing is used in television, computer screens, and other digital displays that use RGB colour models.

Explanation: The transmission of light through optical fibres is based on the principle of Total Internal Reflection (TIR). When light travels from a denser medium (core of the fibre) to a rarer medium (cladding) and strikes the interface at an angle greater than the critical angle, it gets completely reflected back into the core instead of refracting out. This continuous internal reflection allows light to travel long distances through the fibre with minimal loss, even when the fibre is bent. Optical fibres are widely used in telecommunication, internet data transfer, and medical endoscopy.

The Stockholm Convention is not associated with the reduction of greenhouse gases. It focuses on eliminating or restricting the production and use of persistent organic pollutants (POPs) — toxic chemicals that remain in the environment for long periods, such as DDT and PCBs. It does not directly address greenhouse gas emissions or climate change.

Other options (for context)

• Kigali Amendment to the Montreal Protocol: Aims to phase down the use of hydrofluorocarbons (HFCs), which are potent greenhouse gases used in refrigerants — hence it helps reduce global warming.
• Kyoto Protocol: An international treaty adopted in 1997 to reduce greenhouse gas emissions by developed countries, directly targeting climate change.

The Itai-Itai disease is caused by Cadmium (Cd) poisoning. The disease was first identified in Japan, where industrial discharge of cadmium-contaminated water led to severe pollution. People consuming rice grown in this contaminated water suffered from extreme pain in bones and joints, along with kidney damage. The name "Itai-Itai" literally means "ouch-ouch" in Japanese, reflecting the severe pain experienced by victims.

Other options (for context)

• Nickel: Causes dermatitis and allergic reactions but not Itai-Itai disease.
• Chromium: Can cause skin and respiratory problems, not bone-related disorders.
• Mercury: Leads to Minamata disease, not Itai-Itai disease.

Explanation: The Indian Space Research Organisation (ISRO) is headquartered in Bangalore (Bengaluru), Karnataka. It was established in 1969 under the guidance of Dr. Vikram Sarabhai, who is known as the father of the Indian space program. ISRO is India’s national space agency, responsible for space research, satellite launches, and planetary exploration. It developed major missions such as Chandrayaan (Moon mission), Mangalyaan (Mars Orbiter Mission), and PSLV & GSLV launch vehicles.