EST FGEI Past Papers MCQS

The correct answer is Lithium because it possesses the lowest density and lowest atomic mass of all solid metallic elements on the periodic table.

• Step 1 (Density Analysis): Lithium (Li) is an alkali metal with an exceptionally low density of approximately 0.534 g/cm³. This is so light that a block of pure lithium metal can easily float on top of water or oil.
• Step 2 (Atomic Mass): Positioned at atomic number 3, it has an atomic weight of roughly 6.94, making it structurally the least dense solid element at standard room temperature and pressure.
• Incorrect Options:
  • Lead is incorrect because it is a dense, heavy post-transition metal with a high density of 11.34 g/cm³.
  • Mercury is incorrect because it is a dense liquid transition metal with a massive density of 13.53 g/cm³.
  • Silver is incorrect because it is a precious heavy transition metal with a density of 10.49 g/cm³.

The correct answer is Platelets because 'thrombocyte' is the scientific term used to define the cell fragments that facilitate blood clotting.

• Step 1 (Function and Form): Thrombocytes are tiny, colorless, disc-shaped cell fragments produced within bone marrow from larger cells called megakaryocytes. Their primary physiological duty is to aggregate at injury sites to form plugs and stop bleeding.
• Incorrect Options:
  • RBC is incorrect because Red Blood Cells are scientifically referred to as erythrocytes, which are responsible for transporting oxygen throughout the body.
  • WBC is incorrect because White Blood Cells are scientifically termed leukocytes, which form the core defense of the immune system.
  • Serum is incorrect because serum is the clear, amber-colored liquid component of blood that remains after clotting factors and blood cells are entirely removed.

The correct answer is Infra-Red Waves because night vision equipment works by capturing and amplifying ambient infrared light radiation that is invisible to the unaided human eye.

• Step 1 (How Night Vision Works): Objects emit thermal energy in the form of heat, which radiates outward as infrared light. Night vision goggles and scopes gather this infrared light alongside scattered ambient starlight, channeling it through image-intensifier tubes or digital sensors to produce a clear visible display.
• Incorrect Options:
  • Ultra Violet Waves is incorrect because ultraviolet rays have shorter wavelengths than visible light and are primarily emitted by high-energy sources like the sun, making them useless for dark conditions.
  • Radio Waves is incorrect because radio waves have exceptionally long wavelengths used for communication and broadcasting rather than visual imaging.
  • Microwaves is incorrect because microwaves are utilized for radar systems, satellite transmissions, and thermal cooking rather than optical night-vision amplification.

The correct answer is Distance because an odometer is an instrument integrated into vehicles to track the cumulative mileage or distance traveled.

• Step 1 (Instrument Function): Odometers measure distance by registering wheel rotations through a mechanical gear system or digital sensors, multiplying those rotations by the circumference of the tire to determine total mileage.
• Incorrect Options:
  • Velocity is incorrect because the rate of change of position (speed in a given direction) is actively monitored by a speedometer.
  • Acceleration is incorrect because the rate at which a vehicle's velocity increases over time is measured using an accelerometer.
  • Pressure is incorrect because fluid or atmospheric forces are measured using specialized gauges, such as a barometer or a tire pressure gauge.

The correct answer is 32°F because that is the exact temperature value assigned to the freezing point of water on the traditional Fahrenheit scale.

• Step 2 (Scale Calibration): On the Fahrenheit temperature scale, the freezing point of pure water at standard atmospheric pressure is fixed at exactly 32 degrees, while its boiling point sits at 212 degrees. This splits the difference between freezing and boiling into 180 equal intervals.
• Incorrect Options:
  • 0°F is incorrect because 0°F marks the stabilization point of a specialized brine mixture of equal parts ice, water, and salt, which Daniel Fahrenheit used to calibrate his scale baseline.
  • 18°F is incorrect because it is an arbitrary temperature value that holds no significant chemical or physical relationship to water.
  • 47°F is incorrect because it represents a mild liquid room temperature well above the standard thermal freezing point.

The correct answer is 384,400 Km because this represents the mean semi-major axis distance between the centers of the Earth and the Moon.

• Step 1 (Orbital Shape): The Moon orbits Earth in an elliptical track rather than a perfect circle. This means the actual distance constantly fluctuates between its closest point (perigee at roughly 363,300 km) and its farthest point (apogee at roughly 405,500 km).
• Step 2 (Statistical Average): By averaging the orbital extremes across a complete lunar cycle, astronomers establish the standard metric of 384,400 kilometers (roughly 238,855 miles).
• Incorrect Options:
  • 484,400 Km is incorrect because it overshoots the true average lunar orbital radius by 100,000 kilometers.
  • 584,400 Km is incorrect because a distance this high falls entirely outside the gravitational threshold of the Moon's regular orbit around Earth.
  • 684,400 Km is incorrect because it is nearly double the actual distance measured between the two celestial bodies.

The correct answer is Fossils because the scientific term explicitly defines the preserved remnants, impressions, or traces of prehistoric organisms.

• Step 1 (Fossilization): When an organism dies, its soft tissues typically decay quickly, but hard parts like bones, shells, or teeth can become buried beneath layers of sediment. Over millions of years, minerals gradually replace the organic matter, turning it to stone.
• Step 2 (Trace Evidence): Fossils do not have to be physical body parts; preserved footprints, burrows, tracks, and chemical impressions left behind by ancient life are also formally classified as trace fossils.
• Incorrect Options:
  • Minerals is incorrect because minerals are naturally occurring, inorganic solid substances possessing a definite chemical composition, rather than biological remnants.
  • Rocks is incorrect because a rock is a solid aggregate mixture composed of various minerals, forming the structural crust of the Earth.
  • Sand is incorrect because sand is a granular material composed of finely divided rock and mineral particles, primarily quartz, created by weathering.