Consider the following statement with reference to the thunderstorms.

1. Lightning is produced by the clashing of cumulonimbus clouds in the upper air during thunderstorms.

2. During thunderstorms, it is safer to stand below a tree than to sit inside a car.

3. Distance to the storms can be calculated by observing the time difference between lightning and thunder.

Which of the following statements above is/are NOT correct?

The correct answer is option 2, i.e. Statements 1 and 2 are not correct.

• Lightning is produced by discharges of electricity from cloud to cloud or from cloud to ground. Hence statement 1 is not correct.
• Thunder is the loud noise which follows a flash of lightning.
  • Lightning can be seen before thunder can be heard as light travels faster than sound.
  • Since you see lightning immediately and it takes the sound of thunder about 5 seconds to travel a mile, you can calculate the distance between you and the lightning.
  • If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close.
  • Hence statement 3 is correct.
• In a thunderstorm, you should not stand under a tree because the light tends to strike the highest point of everything. Hence statement 2 is not correct.