Q. 1
Atmospheric Sciences
Difficulty: Medium
(1 Mark)
What is the primary mechanism of electric charge separation inside a convective thunderstorm cloud (cumulonimbus)?
💡
Step-by-Step Explanation & Concept Rationale
Non-inductive charging via rebounding collisions between graupel and ice crystals in the mixed-phase zone (-10 °C to -20 °C) leaves graupel negatively charged (settling into lower cloud) and light ice crystals positively charged (lifted to upper cloud anvil).
Q. 2
Atmospheric Sciences
Difficulty: Hard
(1 Mark)
What is the typical charge structure of a mature cumulonimbus thunderstorm?
💡
Step-by-Step Explanation & Concept Rationale
Thunderstorms generally exhibit a tripole charge distribution: upper positive anvil, middle negative core (around -15 °C level), and a localized lower positive charge center.
Q. 3
Atmospheric Sciences
Difficulty: Medium
(1 Mark)
What initiates a cloud-to-ground (CG) lightning flash?
💡
Step-by-Step Explanation & Concept Rationale
The stepped leader originates in the cloud and propagates downward in intermittent luminous steps. As it nears the ground, an upward connecting streamer rises to meet it.
Q. 4
Atmospheric Sciences
Difficulty: Medium
(1 Mark)
What is the 'Return Stroke' in a lightning flash?
💡
Step-by-Step Explanation & Concept Rationale
The return stroke is the bright flash we see: an enormous current pulse (typically 30,000 amperes) propagating upward at roughly one-third the speed of light, heating the channel to ~30,000 K.
Q. 5
Atmospheric Sciences
Difficulty: Easy
(1 Mark)
What is the physical cause of 'Thunder'?
💡
Step-by-Step Explanation & Concept Rationale
The return stroke heats the air column in microseconds to ~30,000 K. The resulting extreme overpressure produces a supersonic cylindrical shock wave that decays into the acoustic rumble of thunder.
Q. 6
Atmospheric Sciences
Difficulty: Easy
(1 Mark)
Using the speed of sound in air (~340 m/s or approx 1 km per 3 seconds), how far away is a lightning strike if you hear thunder exactly 6 seconds after seeing the flash?
💡
Step-by-Step Explanation & Concept Rationale
Because light travels virtually instantaneously (~300,000 km/s), distance = speed of sound x time = 340 m/s x 6 s = 2,040 meters (~2 km).
Q. 7
Atmospheric Sciences
Difficulty: Hard
(1 Mark)
What are 'Sprites' in upper-atmospheric electricity?
💡
Step-by-Step Explanation & Concept Rationale
Sprites are Transient Luminous Events (TLEs): brief, jellyfish-like crimson flashes in the mesosphere caused by quasi-electrostatic fields above powerful thunderstorms.
Q. 8
Atmospheric Sciences
Difficulty: Hard
(1 Mark)
What are 'Blue Jets'?
💡
Step-by-Step Explanation & Concept Rationale
Blue jets are upward-propagating electrical discharges originating near the cloud top and propagating into the stratosphere, emitting blue light from ionized molecular nitrogen.
Q. 9
Atmospheric Sciences
Difficulty: Hard
(1 Mark)
What is the 'Global Electrical Circuit' (GEC)?
💡
Step-by-Step Explanation & Concept Rationale
In the Global Electrical Circuit (C.T.R. Wilson), thunderstorms pump positive charge up to the ionosphere; the circuit is closed by a fair-weather downward return conduction current worldwide.
Q. 10
Atmospheric Sciences
Difficulty: Hard
(1 Mark)
What is the typical fair-weather electric field strength (potential gradient) near the Earth's surface under clear skies?
💡
Step-by-Step Explanation & Concept Rationale
Under fair-weather conditions, Earth's surface carries a negative charge, and the atmospheric electric field is typically 100 to 150 V/m directed downward.
Study Stream Progress:
Showing 10 of 10 Questions (100%)
Ready to Test Your Retention & Speed?
Now that you have reviewed the study questions and rationales, test yourself in our interactive 1-by-1 practice engine or take the full official timed mock exam.