GK: Class 12 General Q&A · Page 2
3,658 free answers on GK (General) for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is 0.1 cm called
0.1 cm (one-tenth of a centimeter) equals 1 millimeter exactly, as the metric system defines 1 cm = 10 mm. There's no special name for 0.1 cm—it's simply expressed as "one millimeter" or "1 mm" in standard practice. The metric prefix system provides dedicated names for powers of ten (kilo- = 1,000×, centi- = 0.01×, milli- = 0.001×, micro- = 0.000001×), making fractional nomenclature like "one-tenth centimeter" unnecessary since "millimeter" already describes this
- GeneralClass 12All
What is 100 mm called
100 mm (one hundred millimeters) equals 10 centimeters, 0.1 meters, or 1 decimeter in metric nomenclature, though "decimeter" is rarely used in everyday practice. The most common ways to express this dimension are "100 millimeters," "10 centimeters," or "0.1 meters" depending on context and magnitude of other dimensions being discussed. In imperial units, 100 mm approximately equals 3.937 inches or roughly 3-15/16 inches. The 100 mm dimension appears frequently across numerous applica
- GeneralClass 12All
What is a micron
A micron (μm), officially called a micrometer, equals 0.001 millimeters or one-millionth of a meter (10⁻⁶ m). While "micrometer" is the correct SI unit term, "micron" remains widely used colloquially in industrial, manufacturing, and scientific contexts. This measurement scale represents dimensions just beyond visible light resolution (visible light wavelengths range 400-700 nanometers or 0.4-0.7 μm), bridging the gap between mechanical machining precision and microscopic/molecular scal
- GeneralClass 12All
Is 0.8 mm 20 gauge
0.8 mm is approximately 20-21 gauge wire, though the exact equivalence depends on which gauge standard you're referencing. In American Wire Gauge (AWG), 20 gauge wire measures approximately 0.812 mm diameter, making 0.8 mm very close to 20 AWG (within 1.5% difference). In body jewelry gauge, 20G typically refers to 0.8-0.9 mm diameter, making 0.8 mm consistent with this designation. The near-equivalence between 0.8 mm and 20 gauge works adequately for general wire and body jewelry app
- GeneralClass 12All
How big is 0 gauge wire
0 gauge wire (0 AWG or 1/0 AWG) has a diameter of approximately 8.25 mm (0.3249 inches exactly), with cross-sectional area of approximately 53.5 mm². This represents large-diameter wire used for high-current electrical service, automotive battery cables, welding leads, and industrial power distribution applications where current demands reach 125-170 amperes depending on installation conditions and insulation type. The gauge designation "0" or "1/0" (pronounced "one-ought") sits
- GeneralClass 12All
What is AWG
AWG (American Wire Gauge) is a standardized system for specifying wire diameter used primarily in North America for non-ferrous electrical wire and cables. The system uses an inverse logarithmic scale where higher gauge numbers indicate smaller wire diameters: 40 AWG (very fine, 0.08 mm) up through 0000 AWG (very large, 11.68 mm). Each six-gauge decrease approximately doubles the wire cross-sectional area and reduces resistance by half, while each three-gauge decrease approximately doubles th
- GeneralClass 12All
How thick is 50 μm
50 μm (micrometers) equals 0.05 mm or approximately 0.002 inches, representing a very thin dimension about half the thickness of a human hair (typical hair ranges 50-100 μm diameter). This measurement scale is common in thin film applications, surface coatings, precision foils, and microscopic material characterization where dimensions fall below readily visible scales yet remain within advanced manufacturing capabilities. Practical examples of 50 μm thickness include: househ
- GeneralClass 12All
How big is a 00 gauge
00 gauge (double-zero or 2/0, also written as 00g) measures 10 mm (3/8 inch) in diameter when referring to body jewelry sizing standards. In the gauge system for piercings and body modification, the progression continues beyond single-zero (0G = 8 mm) into multiple zeros: 00G = 10 mm, 000G (triple-zero) = 11 mm, 0000G (quadruple-zero) = 12 mm, continuing upward approximately 1 mm per step. This represents a large piercing size requiring significant stretching time and care to achieve
- GeneralClass 12All
How big is 22mm
22 mm equals approximately 7/8 inch (exact calculation: 22 ÷ 25.4 = 0.866 inches, while 7/8" = 0.875 inches = 22.23 mm, giving less than 1.5% difference). This dimension represents a moderately large measurement commonly encountered in automotive components, socket wrench sizes, pipe fittings, and mechanical hardware. To visualize 22 mm, it's roughly the diameter of a U.S. penny (19.05 mm) plus a bit more, or about the width of four stacked nickels. The 22 mm size appears frequ
- GeneralClass 12All
What is 30 gauge in mm
30 gauge wire measures approximately 0.254 mm diameter (0.010 inches) according to American Wire Gauge (AWG) standard, representing very fine wire used primarily in specialized applications like transformer windings, precision electromagnets, small resistance coils, and certain electronic components requiring minimal conductor volume. Wire this thin (roughly the thickness of three human hairs) requires extremely careful handling to avoid breakage. For context, 30 AWG is substantially
- GeneralClass 12All
What is bolt size
Bolt size specifications include three critical dimensions: diameter (or gauge/metric designation), thread pitch (threads per inch for imperial or millimeters for metric), and length. For example, "1/4"-20 × 1"" indicates 1/4 inch diameter, 20 threads per inch, 1 inch length. Metric designations like "M8×1.25×40" indicate 8 mm diameter, 1.25 mm thread pitch, 40 mm length. Additional specifications may include head style (hex, socket, carriage, etc.), material grade, and fini
- GeneralClass 12All
What is a 410 screw
410 screw" is likely a misinterpretation or confusion with .410 bore shotgun designation, which isn't a screw at all but rather a shotgun bore diameter (approximately 10.4 mm or 0.410 inches). True screw designations don't use decimal numbers in this format—screws are specified as numbered gauges (#0-#14), fractional inches (like 1/4"-20), or metric (M3, M4, etc.). If the question refers to an actual screw, clarification is needed on the measurement system and specification format.
- GeneralClass 12All
Are #4 and M4 the same size
No, #4 and M4 screws are not the same size, though they're similar enough to cause confusion. A #4 screw has a major diameter of approximately 0.112 inches (about 2.84 mm), while an M4 metric screw has exactly 4.0 mm major diameter. The M4 is approximately 41% larger in diameter than #4, representing a significant difference that prevents any functional interchangeability. Beyond diameter differences, the thread forms are incompatible: #4 screws use Unified Thread Standard angles and
- GeneralClass 12All
What is a no. 1 screw
A #1 screw has a major diameter of approximately 0.073 inches (about 1.85 mm) in the numbered screw size system, representing one of the smallest commonly available machine screw sizes. The numbering system for small screws runs from #0 (smallest, approximately 1.5 mm diameter) through #12 (approximately 5.5 mm diameter), with each increment representing approximately 0.013 inches (0.33 mm) diameter increase. #1 screws are used in eyeglasses, small electronics, precision instruments, and delicat
- GeneralClass 12All
What is M10 thread size
M10 thread designation indicates a metric thread with 10 mm nominal major (outer) diameter, using the ISO metric screw thread standard. The complete specification typically includes pitch: M10×1.5 (coarse thread standard, meaning 1.5 mm distance between adjacent thread crests) or M10×1.25 (fine thread variant for applications requiring higher thread strength or finer adjustment). M10 is a medium-size fastener commonly used in automotive, machinery, structural connections, and gene
- GeneralClass 12All
What is 46 mm in standard
46 mm equals approximately 1-13/16 inches in fractional inch ("standard") measurement (calculated as 46 ÷ 25.4 = 1.811 inches). For common fractional representation, this rounds to 1-13/16" (1.8125 inches, or 46.04 mm) with less than 0.25% error, making it acceptably close for most non-precision applications. Alternatively, 46 mm could be expressed as approximately 1-51/64" for higher precision (1.797 inches, or 45.64 mm). The 46 mm dimension appears in various applications inc
- GeneralClass 12All
How thick is 1mm
1 mm (one millimeter) measures 0.1 cm or approximately 0.039 inches thick, representing the smallest standard division on metric rulers and a dimension easily visible to the unaided eye under normal lighting. To develop tactile and visual reference for 1 mm thickness, consider that a standard credit card is approximately 0.76 mm thick, making 1 mm slightly thicker than a card but noticeably thinner than two cards stacked (1.52 mm). Other common 1 mm references include: the thickness o
- GeneralClass 12All
What size is 7 44 wire in mm
7/44 inch wire equals approximately 4.04 mm in diameter (calculated as 7 ÷ 44 × 25.4 = 4.04 mm). This fractional inch designation represents an uncommon wire size specification, as standard wire sizing typically uses AWG numbers (for smaller sizes), fractional inches in common denominators like 1/16, 1/8, or decimal inches for industrial applications rather than forty-fourths. The 7/44 inch dimension (0.1591 inches) would fall between standard AWG sizes: roughly equivalen
- GeneralClass 12All
What is 20 AWG wire
20 AWG (American Wire Gauge) wire has a diameter of approximately 0.812 mm (0.032 inches), representing relatively thin wire commonly used in electronics, telecommunications, small appliance wiring, and hookup wire applications. The cross-sectional area is approximately 0.52 mm², giving this gauge wire modest current-carrying capacity typically rated at 1-5 amperes depending on insulation type, ambient temperature, and installation conditions. The 20 AWG size is prevalent in seve
- GeneralClass 12All
What size wire is 1.5 mm
1.5 mm diameter wire corresponds to approximately 15 AWG (American Wire Gauge) in the wire gauge system, falling between 14 AWG (1.628 mm) and 16 AWG (1.291 mm). However, it's important to distinguish whether "1.5 mm" refers to wire diameter or cross-sectional area, as European electrical standards often specify wire by cross-sectional area rather than diameter. If "1.5 mm" refers to cross-sectional area (1.5 mm²), this corresponds to wire with approximately 1.38 mm diameter, rou