In India, the most widely used form of renewable energy is Solar Energy. Due to the country’s tropical location, India receives abundant sunlight throughout the year, making solar power a highly viable and sustainable energy source. It is harnessed using solar panels for electricity generation and heating applications under initiatives like National Solar Mission.

• Geothermal energy: Used only in limited pilot projects.
• Hydro-electric energy: Important but not as rapidly expanding as solar.
• Thermal energy: Usually refers to non-renewable coal-based power plants.

Explanation: The ATM (Automated Teller Machine) was invented by John Shepherd-Barron in 1967. He designed the first cash dispensing machine, which was installed by Barclays Bank in London, UK. The first ATM used special paper vouchers impregnated with a radioactive compound instead of plastic cards. The idea revolutionized the banking sector by allowing people to withdraw money anytime without visiting a bank counter. Modern ATMs now use magnetic or chip-based cards, PIN authentication, and networked systems for secure transactions.

Explanation: Nucleons are the particles that make up the nucleus of an atom — namely, protons and neutrons. A positron is not a nucleon; it is the antiparticle of the electron, having the same mass as an electron but a positive charge, and exists outside the nucleus.

Explanation: Thiamine (Vitamin B₁) is a water-soluble vitamin essential for carbohydrate metabolism and proper functioning of the nervous system. Its deficiency causes beriberi, which manifests as muscle weakness, loss of appetite, fatigue, and nerve degeneration. There are two main types of beriberi: dry beriberi (affecting nerves) and wet beriberi (affecting the heart).

Rich Sources: Whole grains, legumes, nuts, meat, eggs, and yeast.

William Harvey, an English physician, discovered the process of blood circulation in 1628. He demonstrated that the heart acts as a pump to circulate blood continuously throughout the body via a closed system of arteries and veins. His work, published in "De Motu Cordis" (On the Motion of the Heart and Blood), laid the foundation for modern cardiovascular physiology.

Other options (for context)

• Mary Anderson: Invented the windshield wiper, not related to medicine.
• Virginia Apgar: Developed the Apgar score for assessing newborn health.
• Robert Feulgen: Discovered a staining technique for DNA, not blood circulation.

Explanation: Edward Jenner, an English physician, is known as the “Father of Immunology.” In 1796, he observed that milkmaids who had previously suffered from cowpox (a mild disease) did not contract smallpox (a deadly viral disease). He tested his hypothesis by injecting a boy with material taken from a cowpox sore and later exposing him to smallpox — the boy did not develop the disease. This led to the development of the first vaccine, derived from the Latin word vacca meaning “cow.”

Significance: Jenner’s discovery laid the foundation of modern immunology and preventive medicine. Smallpox was officially declared eradicated by the WHO in 1980.

The normal body temperature of a healthy human being is approximately 37 °C, which is equivalent to 98.6 °F. This temperature is maintained through a balance between heat production and heat loss in the body. The body’s thermoregulation is controlled by the hypothalamus in the brain to ensure proper functioning of enzymes and metabolic processes.

Other options (for context)

• 98.4 °C: Incorrect — the correct equivalent in Fahrenheit is 98.6 °F, not in Celsius.
• 14.5 °C: Much lower than the human body temperature — such a value would indicate hypothermia or death.
• 25 °C: Represents a mild room temperature, not body temperature.

Explanation: The incorrect pair is Faraday : Diffusion of gases. The diffusion of gases was studied and explained by Thomas Graham, not by Michael Faraday. Graham’s Law states that the rate of diffusion of a gas is inversely proportional to the square root of its density or molar mass. On the other hand, Michael Faraday is famous for his work on electromagnetism and electrolysis. The other pairs are correctly matched with their discoveries.