General Awareness & General Science Capsule

Physical quantities

Quantities which can describe the laws of physics and are possible to measure.

Fundamental Units

The units defined for the fundamental quantities such as Mass ($Kg$), Length ($m$), Time ($s$), Temperature ($K$), Electric Current ($A$), Luminous Intensity ($Cd$), and Amount of Substance ($mol$).

Acceleration

The time rate of change of velocity of a body; it is a vector quantity and its SI unit is $ms^{-2}$.

Projectile Motion

The motion of a body thrown from horizontal making an angle ($\theta$) except $90^{\circ}$, following a curved parabolic path called a trajectory.

Centripetal Force

A force that always acts on a body towards the centre of the circular path during circular motion.

Inertia

The property of a body by virtue of which it opposes any change in its state of rest or of uniform motion in a straight line.

Impulse

A large force acting on a body for a very short interval of time, producing a large change in its momentum; its unit is newton-second.

Simple Harmonic Motion (SHM)

An oscillatory motion of constant amplitude and single frequency under a restoring force proportional to displacement acting towards the mean position.

Mechanical Wave

A wave that requires a material medium (solid, liquid, or gas) for its propagation, such as longitudinal or transverse waves.

Doppler’s Effect

The apparent change in the frequency of a source due to relative motion between the source and the observer.

Triple Point of Water

The temperature at which the three phases of water remain at equilibrium, specifically $273.16\,K$.

Anomalous Expansion of Water

The behavior where the volume of water decreases between $0^{\circ}C$ and $4^{\circ}C$, reaching its minimum at $4^{\circ}C$ before increasing.

Latent Heat

The heat energy absorbed or released at constant temperature per unit mass for a change of state, denoted by $L$.

Bernoulli’s Theorem

States that for a non-viscous and incompressible liquid in streamlined flow, the sum of pressure, kinetic, and potential energy per unit volume remains constant.

Total Internal Reflection

A phenomenon occurring when light travels from a more optically dense medium to a less optically dense one, provided the angle of incidence exceeds the critical angle.

Myopia

Nearsightedness caused by an eyeball that is too long or a lens that is too spherical, corrected with concave lenses.

Coulomb’s Law

The electrostatic force between two stationary point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them ($F = K\frac{q_a q_b}{r^{2}}$).

Resistance

The opposition that a substance offers to the flow of electric current, with the S.I. unit being the ohm ($\Omega$).

Electrolysis

The chemical effect of current where an electric current passed through a solution decomposes it into positive and negative ions.

Curie Temperature

The particular temperature above which a ferromagnetic substance loses its magnetism; for iron, this is $770^{\circ}C$.

Escape Velocity

The minimum velocity required for a body to be projected from the earth's surface to escape its gravitational field; for Earth, this is $11.2\,km/s$.

Compound

A substance made up of two or more elements chemically combined in a fixed ratio by weight, such as $H_2O$ or $NaCl$.

Colloids

A heterogeneous mixture with particle sizes intermediate between solutions and suspensions (between $1\,nm$ and $100\,nm$).

pH Scale

A scale ranging from $0$ to $14$ used to measure the strength of an acid or base, where $7$ is neutral and lower values are acidic.

Isotopes

Atoms which have the same atomic number but different mass numbers, with similar chemical properties but different physical properties.

Aqua Regia

A yellow-orange fuming mixture of nitric acid and hydrochloric acid in a molar ratio of $1:3$, capable of dissolving gold and platinum.

Annealing

The process of slow and uniform cooling of molten glass to prevent internal strain.

Vulcanisation

The process of heating raw rubber with sulphur and additives at $373\,K$ to $415\,K$ to make the rubber stiffer.

Exothermic Reaction

A chemical reaction in which heat is released along with the formation of products.

Allergy

A condition treated with Antihistamines, which are drugs used to relieve symptoms of cold and allergies.

Cytology

The branch of biology concerned with the study of the cell.

Mitochondria

The "power house" of the cell where energy is released in the form of $ATP$ (adenosine tri-phosphate) molecules.

Plasmolysis

The phenomenon where a living plant cell loses water through osmosis, leading to shrinkage of contents away from the cell wall.

Synapse

The junction between a nerve cell and another cell; the space between them is known as the synaptic cleft.

Hematology

The scientific study of blood.

Sinoatrial node

The part of the human heart that produces the electrical pulses driving heart contractions.

Binomial Nomenclature

A system formulated by Carolus Linnaeus in "Species plantarum" where each name is expressed in two parts: generic name and specific name.

Quaternary

The classification rank Kingdom includes Category such as Kingdom Monera, Kingdom Protista, Kingdom Fungi, Kingdom Plantae, and Kingdom Animalia.

Paleolithic Age

The Old Stone Age ($500,000\,B.C. - 10,000\,B.C.$) where humans were hunters and gatherers using unpolished stone tools.

Boustrophedon

The writing style of the Indus Valley script where lines alternate from right-to-left and left-to-right.

Tripitakas

The 'Threefold Basket' of Buddhist scriptures in Pali, consisting of Vinaya Pitaka, Sutta Pitaka, and Abhidhamma Pitaka.

Grand Trunk Road

A major highway built during the reign of Sher Shah Suri, running from Calcutta to Peshawar.

Doctrine of Lapse