GK: Class 12 General Q&A · Page 19
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
feet in inches
One foot (1 ft) equals 12 inches (12 in), a fundamental conversion in the imperial measurement system used primarily in the United States and occasionally in other countries including India for certain measurements like height and construction materials. The relationship derives from historical definitions where the foot was standardized as 12 inches, with the inch itself defined as 2.54 centimeters exactly by international agreement. Understanding this conversion enables seamless translation
- GeneralClass 12All
KFC full form
KFC stands for "Kentucky Fried Chicken," an American fast-food restaurant chain specializing in fried chicken, headquartered in Louisville, Kentucky, and founded by Colonel Harland Sanders in 1952. The chain is famous for its "Original Recipe" fried chicken prepared using a secret blend of 11 herbs and spices that Sanders developed, marketed as unique and proprietary—though the exact recipe remains closely guarded, it reportedly includes salt, pepper, thyme, and other common spices. KFC
- GeneralClass 12All
Why does inert gases placed in zero
Inert gases (noble gases: helium, neon, argon, krypton, xenon, radon) are placed in Group 0 (also called Group 18) of the periodic table because they have zero valency—meaning they generally do not form chemical bonds with other elements under normal conditions. This zero valency results from their complete outer electron shells: helium has 2 electrons filling its first shell completely, while other noble gases have 8 electrons in their outermost shells (octet configuration), representi
- GeneralClass 12All
tan20°tan40°tan60°tan80° = 3
This trigonometric expression demonstrates an interesting mathematical property: tan20° × tan40° × tan60° × tan80° = 3. This result can be verified numerically using calculators or derived using trigonometric identities. The proof relies on the relationship: tan(60° - θ) × tan(60° + θ) = (√3 - tan θ)/(√3 + tan θ) × (√3 + tan θ)/(√3 - tan θ) through angle sum/difference formulas an
- GeneralClass 12All
Nephew meaning in Hindi
"Nephew" in Hindi is "भतीजा" (bhateeja) when referring to a brother's son (paternal nephew) or "भांजा" (bhaanja) when referring to a sister's son (maternal nephew). This distinction reflects Hindi language structure that differentiates relationships based on whether they're from the father's side or mother's side of the family, providing more specific kinship terminology than English. Similarly, "niece" (a brother's or sister's daughter) translates as "भतीजी" (bhateejee) for brother's daughte
- GeneralClass 12All
Crop survey
Crop survey refers to systematic data collection and assessment of agricultural production covering crop area, yield estimates, production forecasts, crop health, pest and disease incidence, irrigation status, and farming practices across regions or entire countries. These surveys employ various methodologies including random sampling, satellite remote sensing, drone imagery, field inspections by agricultural officials, and farmer interviews to gather comprehensive agricultural statistics. In
- GeneralClass 12All
To which period does this element belong
This question typically appears in chemistry examinations where students are given an element's atomic number, electronic configuration, or other properties, and must identify which period (horizontal row) in the periodic table the element belongs to. Elements in the same period have the same number of electron shells or energy levels. The periodic table contains seven periods: Period 1 (Hydrogen, Helium - 1 shell), Period 2 (Lithium through Neon - 2 shells), Period 3 (Sodium through Argon -
- GeneralClass 12All
Very exciting can be new country travelling to a
This appears to be a sentence rearrangement or grammar exercise where words are presented out of order and need to be arranged into a grammatically correct, meaningful sentence. Rearranging these words properly yields: "Travelling to a new country can be very exciting." This sentence follows standard English grammar with subject ("Travelling to a new country"), verb ("can be"), and complement ("very exciting"), expressing the common experience that international travel generates excitement th
- GeneralClass 12All
Nagaram
"Nagaram" (నగరం) is a Telugu word meaning "city" or "town," commonly appearing in place names across Andhra Pradesh and Telangana states. Many localities and municipalities include "Nagaram" as a suffix—examples include Uppal Kalan (sometimes referred to with Nagaram suffix), areas around Hyderabad, and various towns in Telugu-speaking regions. The term derives from Sanskrit "nagara" (नगर), which also means city or town, demonstrating the linguistic evolution from Sanskrit to Dravidian
- GeneralClass 12All
What is the difference between a cylinder and a cone
The main differences between a cylinder and a cone are shape, volume, and surface area characteristics: a cylinder has two parallel, congruent circular bases connected by a straight curved surface (uniform cross-section throughout its height), while a cone has one circular base that tapers uniformly to a single point (apex) through a slanted curved surface. Visually, cylinders maintain constant width from bottom to top (like a can or pipe), while cones start wide and narrow to a point (like a
- GeneralClass 12All
What is the main difference between a circle and a sphere
The fundamental difference between a circle and a sphere is dimensionality: a circle is a two-dimensional (2D) shape—a flat curve on a plane where all points are equidistant from a center point—while a sphere is a three-dimensional (3D) object where all points on its surface are equidistant from a center point in space. A circle exists only on a flat surface (like paper) with area but no thickness, while a sphere is a solid object occupying space with surface area and volume.
- GeneralClass 12All
How does a right circular cone look like
A right circular cone looks like a solid three-dimensional shape with a flat circular base and a curved surface that tapers uniformly from the base edge up to a single point (the apex or vertex) directly above the center of the base. Imagine a classic pointed party hat, ice cream cone, traffic cone, or the shape of a volcano—these exemplify right circular cones. The "right" means the apex sits precisely perpendicular above the base center, creating perfect symmetry around the vertical a
- GeneralClass 12All
What is the relationship between the cylinder compared to the sphere
The geometric relationship between cylinders and spheres involves elegant volume and surface area connections discovered by Archimedes. Most notably: a sphere inscribed in a cylinder (where the sphere exactly fits inside, touching the cylinder's curved surface and both bases) has volume exactly ⅔ of the cylinder's volume, and the sphere's surface area equals the cylinder's lateral (curved) surface area. Specifically, if the cylinder has radius r and height 2r (exactly containing a sphere of r
- GeneralClass 12All
What is the difference between total surface area and curved surface area of a cone of height h, slant height l, and radius r
For a cone with height h, slant height l, and radius r, the Curved Surface Area (CSA) is πrl (the slanted conical surface wrapping around from apex to base edge), while the Total Surface Area (TSA) is πrl + πr² = πr(l + r), adding the flat circular base area (πr²) to the curved surface. The fundamental difference is whether you include the circular base: CSA measures only the slanted wrap-around surface, while TSA includes everything—curved surface plus the bott
- GeneralClass 12All
Do HVAC return ducts need to be insulated
HVAC return ducts need insulation primarily when they pass through unconditioned spaces (attics, crawlspaces, garages, or outdoors) to prevent condensation and energy loss, but typically don't require insulation when running through conditioned spaces (inside living areas). The key considerations are: (1) Condensation prevention—in cooling season, cool return air passing through hot, humid unconditioned spaces can cause duct surfaces to drop below dew point, leading to condensation, moi
- GeneralClass 12All
How do you find the TSA of a right circular cylinder
To find the Total Surface Area (TSA) of a right circular cylinder with radius r and height h, use the formula TSA = 2πr(h + r) or equivalently TSA = 2πrh + 2πr², which accounts for the curved lateral surface (2πrh) plus both circular bases (πr² each, totaling 2πr²). Measure or identify the cylinder's radius (from center to edge of circular base) and height (perpendicular distance between bases), ensure units are consistent, then substitute into the formula and
- GeneralClass 12All
What are the different types of cones
The main types of cones in geometry include: (1) Right circular cone—apex directly above the center of a circular base with the axis perpendicular to the base, the most common and symmetric cone type; (2) Oblique circular cone—apex offset so the axis is not perpendicular to the circular base, creating asymmetry; (3) Elliptical cone—base is an ellipse rather than a circle; (4) Right cone with non-circular base—apex is directly above (perpendicular) a base that's polygon
- GeneralClass 12All
What is the difference between a right circular cone and a normal cone
A right circular cone is a specific type of cone where the axis (the line from the apex to the base center) is perpendicular to the circular base, creating perfect symmetry. In contrast, an oblique cone has its apex positioned off-center so the axis is not perpendicular to the base, creating asymmetry. The term "normal cone" isn't standard mathematical terminology—most references to "cone" without qualification assume a right circular cone unless otherwise specified. The key dif
- GeneralClass 12All
How to calculate the overall diameter of a cable
To calculate the overall diameter of a multi-conductor cable (cable containing multiple wires, conductors, or components), you need to know the configuration and diameters of the individual components. For round cables with conductors arranged in a circle around a central core or filler, use: Overall Diameter ≈ 2r + D_conductor, where r is the radius from cable center to conductor centers and D_conductor is individual conductor diameter. For simpler two-conductor or coaxial cables, meas
- GeneralClass 12All
How to size plenum box for HVAC
To size an HVAC plenum box (the large chamber connecting the furnace/air handler to the duct system), follow these guidelines: the plenum should be sized to handle the system's total CFM with sufficient volume to distribute air evenly among branch ducts without creating excessive velocity or turbulence. The supply plenum (immediately above/beside the air handler) typically has cross-sectional area 1.5-2 times the blower outlet area and should maintain air velocity below 900 FPM (feet per minu