GenEd Science covers physics, chemistry, biology, earth science, and environmental science at a general-knowledge level. Expect questions on the Big Bang, the mole concept, classification of organisms, and applied topics like e-waste.
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Sample questions with answers and explanations
Sample 1
Which environmental phenomenon is caused by the accumulation of greenhouse gases like carbon dioxide and methane, leading to the trapping of heat in the Earth's atmosphere?
AOzone layer depletion
BAcid rain
CEutrophication
DGreenhouse effect✓
Answer: D
The greenhouse effect is the warming that happens when certain gases in Earth's atmosphere — carbon dioxide, methane, water vapor — trap heat. Sunlight passes through the atmosphere and warms the surface. The surface emits some of that energy back as heat (infrared radiation). Greenhouse gas molecules absorb that outgoing heat and re-emit it in all directions, including back down — keeping the planet warmer than it would be otherwise. Without ANY greenhouse effect, Earth would be a frozen rock; with TOO MUCH (from fossil fuel burning), the planet warms beyond what ecosystems are adapted to.
Why the other choices are wrong
A. Ozone layer depletion is a separate problem caused by chlorofluorocarbons (CFCs), not by greenhouse gases.
B. Acid rain comes from sulfur dioxide and nitrogen oxides, not from greenhouse gas accumulation.
C. Eutrophication is excess nutrients overloading water bodies — unrelated to atmospheric heat trapping.
Sample 2
According to Newton’s First Law of Motion, an object at rest will remain at rest, and an object in motion will remain in motion unless acted upon by an external force. This property is known as:
AAcceleration
BInertia✓
CMomentum
DVelocity
Answer: B
Inertia is an object's tendency to resist changes in its motion — to keep doing what it's doing. A heavy box sits still until pushed; once moving, a sliding box keeps moving until friction stops it. Isaac Newton stated this in his First Law: an object at rest stays at rest, and an object in motion stays in motion at the same speed and direction, unless acted on by a force. Mass measures inertia: heavier objects have more inertia and resist motion change more strongly. When a bus brakes hard and you lurch forward, that's your inertia trying to keep you moving at the bus's old speed.
Why the other choices are wrong
A. Acceleration is a change in velocity — the EFFECT of a force, not the resistance to one.
C. Momentum is mass times velocity — a quantity of motion, not the resistance to motion change.
D. Velocity is speed plus direction — the motion itself, not the resistance to changing it.
Sample 3
What is the primary cause of the seasonal changes experienced on Earth?
AThe distance between the Earth and the Sun varies throughout the year.
BThe Earth's axial tilt as it revolves around the Sun.✓
CThe speed of the Earth's rotation on its axis.
DThe influence of the Moon's gravitational pull on the tides.
Answer: B
Earth's axis is tilted about 23.5 degrees relative to its orbit around the Sun. As Earth orbits over the year, the same hemisphere alternately leans toward and away from the Sun. When the Northern Hemisphere leans toward the Sun (around June), it gets more direct sunlight and longer days — that's summer there. Six months later it leans away, gets oblique sunlight and shorter days — winter. Earth's distance from the Sun changes only slightly during the orbit and isn't what causes the seasons; the axial tilt is.
Why the other choices are wrong
A. Earth's distance from the Sun varies only slightly across the year and isn't the main driver of seasons.
C. Rotation speed determines day length but is roughly constant; it doesn't cause seasonal change.
