Question

A TV tower has a height of 100 meter. If the coverage range is to be made three times then the height of the tower should be increased by.

Options

• 500 m

• 600 m

• 700 m

• 800 m

Answer 1

800 m

Explanation -

`"Coverage range" ∝ sqrt"height of power"`

`"Coverage" ∝ sqrt100`        ...(i)

Let h be height of tower to tripple coverage

`3 xx "coverage" ∝ sqrt"h"`       ...(ii)

dividing eqn (i) and (ii)

`1/3 = sqrt(100/"h") => "h" = 900`

As a result, the height should be increased by 900 - 100 = 800 metres.