Assertion: The lightening conductor at the top of high building has sharp pointed ends.
Reason: The surface density of charge at sharp points is very high resulting in setting up of electric wind.

Options

A. if both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
C. if Assertion is true, but the Reason is false.
D. if both Assertion and Reason are false

Answer

a

Explanation

A charged cloud induces opposite charge on pointed conductors. At sharp points of the conductor surface density of charge is very high and charge begins to leak from the pointed ends by setting up oppositely charged electric winds. This wind, when comes in the contact with the charge cloud, neutralizes some of its charge lowering the potential difference between the cloud and the building. Theis reduces the changes of lightening striking the building [if the lightning strikes the building, the charge is conducted to the earth and the building remains safe.