10 questions ยท Form 3 Science Bab 9: Space Weather
Why is high-frequency (HF) radio communication frequently disrupted during solar activity flares?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Why is high-frequency (HF) radio communication frequently disrupted during solar activity flares?
Answer: A
Increased X-ray and UV radiation from solar flares ionizes the D-layer of the ionosphere, absorbing HF radio waves instead of reflecting them.
2. Which human technology infrastructure on ground is most vulnerable to damage from severe geomagnetic storms?
Answer: A
Geomagnetically induced currents (GICs) flow into power lines and can overload, damage, or burn out high-voltage transformers.
3. Which solar phenomenon involves massive loops of glowing plasma held in place by magnetic field lines above the photosphere?
Answer: A
Solar prominences are huge, arched loops of dense glowing plasma anchored in the photosphere and extending into the corona.
4. Which chemical elements make up the vast majority of the Sun's mass?
Answer: B
The Sun consists of roughly 73% hydrogen and 25% helium, with trace amounts of heavier elements.
5. What causes the grainy pattern known as 'granules' on the Sun's photosphere surface?
Answer: B
Granules are tops of convection cells in the solar mantle where hot plasma rises in the center and cools down at edges.
6. What is the primary heat generation process operating at the core of the Sun?
Answer: B
The Sun's core generates massive energy via nuclear fusion, fusing hydrogen nuclei into helium under extreme pressure and heat.
7. Which occupational group faces elevated radiation exposure risks during severe solar radiation storms?
Answer: B
High-altitude flights over polar regions receive higher cosmic and solar radiation doses because Earth's magnetic shielding is thinner near the poles.
8. What phenomenon occurs when huge clouds of magnetized plasma are thrown off the Sun's atmosphere into space at high velocities?
Answer: A
Coronal Mass Ejections (CMEs) release billions of tons of coronal material containing magnetic fields outward at high speeds.
9. How can strong solar flares and coronal mass ejections (CMEs) affect artificial satellites orbiting Earth?
Answer: B
Intense solar radiation expands Earth's upper atmosphere, increasing orbital drag while high-energy particles disrupt sensitive satellite electronics.
10. What is the name given to auroras occurring specifically around the Southern magnetic pole?
Answer: B
Aurora Australis refers to southern light displays, while Aurora Borealis occurs near the Northern magnetic pole.