General Science and Engineering Knowledge Quiz

Chatoyancy is the optical phenomenon where a gemstone displays a narrow band of reflected light that resembles a cat's eye. The most famous chatoyant gemstones are chrysoberyl cat's eye and tiger's eye quartz.

Seaborgium (Sg) is a synthetic element with atomic number 106, classified as a transition metal in group 6 of the periodic table. It's named after Glenn T. Seaborg and does not occur naturally.

The 'turn your head and cough' test is a standard physical examination technique for checking inguinal hernias. Coughing increases abdominal pressure, which can cause a hernia to bulge and become detectable to the doctor.

A shooting star is actually a meteor - a small piece of rock or dust burning up in Earth's atmosphere. As it enters the atmosphere at high speed, friction causes it to glow and create a visible streak of light.

Acid rain typically has a pH between 4 and 6, which is below the neutral pH of 7. This acidity comes from sulfur dioxide and nitrogen oxides reacting with water in the atmosphere to form sulfuric and nitric acids.

Daltonism is a specific type of color blindness named after John Dalton, who first described the condition. It primarily causes difficulty distinguishing between red and green colors due to cone cell defects in the retina.

For two gears to mesh properly and transmit power, they must have the same module (a parameter defining gear tooth size). The module is inversely related to the diametral pitch and is a fundamental design parameter. If two gears are in mesh, their modules must be identical regardless of the power transmitted or rotational speed. The power (10 HP) and speed (1000 RPM) are irrelevant for determining the module of the second gear.

Steel is defined as an alloy of iron and carbon with carbon content typically between 0.02% and 2% by weight. The 2% upper limit is a critical distinguishing factor between steel and cast iron (which has higher carbon content, typically 2-4%). Beyond 2% carbon, the material is classified as cast iron, not steel. Options A (0.2%) is too low for most steels, C (6%) and D (20%) are in the cast iron range.

For a cantilever beam, maximum bending stress occurs at the fixed end where bending moment is maximum. The bending moment M at the fixed end equals the load multiplied by the distance from the fixed end: M = 50 N x 120 mm. Bending stress is given by sigma = M/Zc, where Zc is the section modulus. Therefore sigma = (50 x 120)/Zc. Option A incorrectly uses the denominator format, option B uses the wrong moment arm (80 mm would be the distance to the free end), and option C incorrectly multiplies by Zc instead of dividing.

The endurance limit (or fatigue limit) is the maximum stress level below which a material can endure an infinite number of load cycles without failure. This is a critical concept in fatigue design for components subjected to repeated loading.

Night vision devices work by detecting infrared radiation, which is emitted by all objects based on their temperature. This allows visualization in darkness by sensing heat patterns rather than visible light.

Starting from origin (0,0): North 12 km → (0,12), East 15 km → (15,12), West 15 km → (0,12), South 18 km → (0,-6). Final position is (0,-6), which is 6 km from starting point. The east and west movements cancel out completely.

Hole: 10mm (+0.050, -0.020) = 9.980 to 10.050 mm. For clearance 0.018 to 0.110 mm: Shaft max = Hole max - 0.018 = 10.050 - 0.018 = 10.032, Shaft min = Hole min - 0.110 = 9.980 - 0.110 = 9.870. But this doesn't match any option. Rechecking with shaft dimensions: Option D (9.940 to 9.962) gives clearance range of (9.980-9.962=0.018) to (10.050-9.940=0.110), which matches requirements.

Color blindness is X-linked recessive. A color-blind woman (XcXc) passes one Xc to son (making him XcY - affected) and one Xc to daughter (making her XcX, where X is normal father's X). Daughter is a carrier but not affected, while son is affected. This is because males have only one X chromosome.

Nitroglycerine is a powerful explosive used in dynamite and mining. The other options are not explosives - Phosphorus Trichloride (chemical reagent), Mercuric oxide (inorganic compound), and Graphite (form of carbon used in pencils and electrodes).

S. Chandrashekhar (Subrahmanyan Chandrasekhar) calculated the mass limit (1.44 solar masses) for white dwarf formation, now known as the Chandrasekhar Limit. He won the Nobel Prize in Physics in 1983 for this work. Hubble, Hawking, and Weinberg made contributions in other areas of cosmology.

A barometer is a scientific instrument used to measure atmospheric pressure. It helps in weather forecasting as pressure changes indicate approaching weather systems. Other options measure different quantities - hygrometer (humidity), flowmeter (flow rate), thermometer (temperature).

For a mass-spring system, natural frequency ωn = √(k/m), where k is stiffness and m is mass.

Poisson's ratio is defined as the negative ratio of lateral (transverse) strain to longitudinal (axial) strain under uniaxial loading.