Question
Explain the process that causes lightning.
✓
Answer
During a storm formation, under certain conditions, warm air rises to great heights, and the low temperature there changes water droplets into ice particles. Strong winds blowing upwards and downwards result in rubbing between water droplets and ice particles. This generates electric charges within clouds. Ice particles are positively charged, and they move upwards in the upper part of the clouds. Water droplets are negatively charged and occupy the lower part of the clouds. When negatively charged water droplets in the lower part of the cloud move closer to the ground, the trees, buildings, and the ground become positively charged. Normally, air acts as an electrical insulator and does not let opposite charges meet. This insulating property of the air breaks down when the build-up charges becomes very large. A sudden flow of charges takes place, resulting in a bright flash of light called lightning. Lightning can occur as opposite charges collide within a cloud, between clouds, or between clouds and the ground. Lightning rapidly heats the air around it. This results in expansion of air to produce a loud sound called thunder.
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Match the organisms in Column $I$ with their action in Column $II.$
→→| Column I | Column II | ||
|
$(i)$
|
Bacteria
|
$(a)$
|
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|
|
$(ii)$
|
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|
$(b)$
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|
$(iii)$
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|
$(c)$
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|
|
$(iv)$
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Yeast
|
$(d)$
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|
$(v)$
|
A protozoan
|
$(e)$
|
Causing cholera
|
|
$(vi)$
|
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|
$(f)$
|
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|
|
|
$(g)$
|
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|
|
