Correct: A. Pascal

The Pascal (symbol: Pa) is the SI unit of pressure, named after the French mathematician and physicist Blaise Pascal. It is defined as one Newton of force applied over an area of one square meter 1 N/m. Pressure is a measure of how "concentrated" a force is; for example, wearing snowshoes reduces pressure by spreading your weight over a larger area.

Correct: B. Thermodynamics

The Law of Conservation of Energy, also known as the First Law of Thermodynamics, states that the total energy of an isolated system remains constant; energy can be transformed from one form to another (such as potential to kinetic), but it can never be created or destroyed. This is a fundamental principle of physics that applies to everything from a bouncing ball to a dying star.

Correct: C. Hertz

The Hertz (symbol: Hz) is the SI unit of frequency, defined as one cycle per second. It is used to measure anything that repeats periodically, such as sound waves, radio waves, or the "clock speed" of a computer processor (measured in GigaHertz). It was named after Heinrich Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves.

Correct: D. Convex

The human eye contains a biconvex lens (also called a converging lens). This lens is flexible and can change its shape to focus light from objects at different distances onto the retina at the back of the eye. This process of changing shape is called "accommodation." Interestingly, the lens actually focuses the image onto the retina upside down!

Correct: D. Neutron

The neutron is the subatomic particle that carries no electrical charge (it is "neutral"). Along with positively charged protons, neutrons are located in the nucleus at the center of an atom. The number of neutrons in an atom determines its "isotope"; for example, Carbon-12 and Carbon-14 have the same number of protons but different numbers of neutrons.

Correct: A. Violet

In the visible light spectrum, violet light has the shortest wavelength, ranging from about 380 to 450 nanometers. Because wavelength and frequency are inversely related, violet light also has the highest frequency and the most energy of any color we can see. Colors with even shorter wavelengths, like ultraviolet, are invisible to the human eye.

Correct: D. Zero

An ideal conductor is a theoretical material that has zero electrical resistance. This means that an electric current can flow through it indefinitely without losing any energy as heat. While no material is a perfect conductor at room temperature, certain materials become "superconductors" with zero resistance when they are cooled to extremely low temperatures.

Correct: C. 11.2 km/s

Escape velocity is the minimum speed an object must reach to break free from the gravitational pull of a celestial body without further propulsion. For Earth, the escape velocity is approximately 11.2 km/s (about 25,000 mph. If a rocket reaches this speed, it can leave Earth's orbit and travel into deep space.

Correct: B. Dioptre

The power of a lens is measured in Dioptres (D). It is defined as the reciprocal of the focal length of the lens in meters P = 1/f. A convex (converging) lens has positive power, while a concave (diverging) lens has negative power.

Correct: C. Weber

The Weber (Wb) is the SI unit of magnetic flux. It represents the total amount of magnetic field passing through a given area. One Weber is equal to one Tesla-meter squared 1 Wb = 1 Tm.

Correct: C. Candela

The candela (cd) is the SI unit of luminous intensity. It measures the amount of light emitted by a light source in a particular direction, weighted by how the human eye perceives brightness.

Correct: A. John Dalton

John Dalton is considered the "father of modern atomic theory." In the early 1800s, he proposed that all matter is composed of tiny, indivisible particles called atoms, that atoms of a given element are identical in mass and properties, and that chemical reactions involve the rearrangement of these atoms.

Correct: B. Farad

The Farad (F) is the SI unit of capacitance, named after the English physicist Michael Faraday. It measures the ability of a component (a capacitor) to store an electric charge. One Farad is defined as the capacitance that stores one Coulomb of charge when a potential of one Volt is applied.

Correct: A. Isobar

An isobar is a line on a weather map that connects points of equal atmospheric pressure. Meteorologists use isobars to identify areas of high and low pressure, which helps them predict wind speed and direction.

Correct: B. Speed of Light

General Relativity predicts that changes in a gravitational field propagate as waves at exactly the speed of light (c). The 2015 detection of gravitational waves from merging black holes confirmed that these ripples travel across the universe at approximately 299,792,458 meters per second. This finding ensures that gravity adheres to the universal speed limit, preventing instantaneous 'action at a distance.'

Correct: C. Bose-Einstein Condensate

A Bose-Einstein Condensate (BEC) occurs when atoms are cooled so much that they collapse into their lowest quantum state and act as a single 'super-atom.' This allows scientists to observe quantum mechanical effects on a macroscopic scale, which are usually hidden at higher temperatures. BECs were first predicted in the 1920s but were not experimentally created until 1995.

Correct: C. Higgs Boson

The Higgs Boson is the physical manifestation of the Higgs field, which permeates the entire universe. Particles gain mass based on how strongly they interact with this field, similar to how it is harder to move through water than through air. Its discovery at CERN in 2012 was the final 'missing piece' of the Standard Model.

Correct: A. Inflation

Cosmic Inflation is a theory proposed to explain why the universe looks so uniform and flat in all directions. It suggests that the universe expanded by a factor of at least 10 to the power of 26 in less than 10 to the power of -32 seconds. This rapid stretching smoothed out any irregularities and set the stage for the formation of galaxies.

Correct: C. Carnot Cycle

The Carnot Cycle is an idealized, reversible cycle consisting of two isothermal and two adiabatic processes. Nicolas Lonard Sadi Carnot proved that no engine can be more efficient than a Carnot engine operating between the same two temperatures. It serves as a theoretical benchmark for engineering real-world engines and power plants.

Correct: A. Seebeck Effect

The Seebeck Effect is the basis for thermocouples, which are used to measure temperature with high precision in industrial and scientific settings. When one junction of the two metals is heated while the other is kept cold, an electric current is generated. This effect is also utilized in Radioisotope Thermoelectric Generators (RTGs) to power deep-space probes like Voyager.

Correct: D. Weak Nuclear Force

The Weak Nuclear Force is the only interaction capable of changing one type of quark into another, which is the process that drives beta decay. It has an extremely short range, acting only over distances smaller than the diameter of a proton. While it is called 'weak,' it is vital for the nuclear fusion processes that allow the Sun to produce energy.

Correct: B. Gauss's Law

Gauss's Law is one of Maxwell's four equations that form the foundation of classical electromagnetism. it provides a powerful way to calculate electric fields for highly symmetrical charge distributions, like spheres or cylinders. It essentially tells us that electric field lines originate from positive charges and terminate on negative ones.

Correct: B. Reynolds Number

The Reynolds Number (Re) is the ratio of inertial forces to viscous forces within a moving fluid. A low Reynolds Number indicates 'laminar' flow, where the fluid moves in smooth, parallel layers, while a high number indicates 'turbulent' flow characterized by eddies and chaotic changes. This value is critical for designers of aircraft, ships, and blood-flow monitoring systems.

Correct: B. Neutron

Neutrons are neutral particles found in the nucleus of almost every atom, and their internal quark composition determines their mass and lack of charge. Protons, by contrast, are made of two 'up' and one 'down' quark, giving them a positive charge. The 'Strong Force' holds these quarks together so tightly that they can never be found individually.

Correct: B. Boltzmann Constant

The Boltzmann Constant (k) is a bridge between macroscopic physics (temperature) and microscopic physics (the motion of individual atoms). It appears in the Ideal Gas Law and is essential for the study of statistical mechanics and entropy. It is approximately 1.38 x 10^-23 Joules per Kelvin.

Correct: A. Zeroth Law

The Zeroth Law is called so because it was recognized after the first three laws but is more fundamental, providing the logical basis for the existence of thermometers. It ensures that 'temperature' is a measurable property that can be compared across different systems. Without this law, we couldn't say that two objects are the same 'hotness' just by using a third tool.